Ultimate Guide to Raised Bed Gardening

Date:5/21/2018
Author:Terry L.
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Photo by Kenan Kitchen on Unsplash

Growing a vegetable garden has so many benefits - you know where your food came from, you can have all the fresh herbs and save so much money.

If you dream of plucking lush greens and juicy, fat tomatoes from your own raised garden bed, read on. Or if you've tried that and it didn't work out so well, don't give up! This guide will tell you what you need to do to produce flourishing crops like a champ - from first plans to final harvest.

What's in this guide

  1. How to choose the best garden location
  2. Choosing vegetables
  3. Design & materials for raised garden beds
  4. What kind of soil is best?
  5. Prepping and planting your raised bed
  6. Caring for your garden
  7. Dealing with garden pests & disease
  8. Harvesting your crops & saving seed
  9. How can I find my local cooperative extension service?

How to choose the best garden location

6 hours of sunshine, minimum

The experts at the Michigan State University Extension say most vegetables and herbs need 6 hours of sunlight minimum, but 8 to 10 are better.

View your potential site at all times of the day - a spot could be sunlit in the morning but in shadows after lunch. Keep the season in mind, too. A site that's sunny in very early spring might be shady once nearby trees leaf out. The MSU Extension also recommends facing beds west or south, if possible. 

The closer to water, the better

Don't depend on rain to water your garden. Young plants especially need regular watering, and you'll need to plan on doing that yourself. This chore will be easier (and more likely to get done) if your garden is near an outdoor faucet or your house.

Decks and balconies need to handle extra weight

Will your garden be on a wood deck, balcony, or rooftop? If yes, be sure the structure can support the combined weight of the container(s), plants and wet soil. Wet dirt is heavy!

Don't plant around trees or shrubs

Thinking of building a raised garden around trees in your yard? The Nebraska Extension says nope: "When soil is piled over a root system, it immediately puts the lower roots out of range of their oxygen source. Roots begin to die, starting the tree on a long slow decline and, eventually, death."

Choosing Vegetables

If it can grow in the ground, it can grow in your raised bed. So grow what you like! Your kids can say no to Brussels sprouts and you can say fine, spinach it is. Your vegetable choices might be limited by plant spacing needs. Vegetables that grow underground, like carrots, can be planted closer together than bushy plants. Your garden may only have room for a single cucumber plant - vines can reach 8 feet long! Refer to seed packets and plant labels for specific information.

You can increase your crop in a limited space by growing up - plant vining vegetables on supports like poles and trellises.

What vegetables should you grow?

Plant what you want to eat but know that some vegetables are easier to grow than others. In general, easy-to-grow veggies include most tomatoes, zucchini, radishes, leafy greens, leeks, onions, garlic, shallots, snow peas, snap peas, short carrots, beets, okra, turnips, sweet potatoes, and bush beans.

Some vegetables can be difficult for backyard gardeners. The divas include broccoli, cauliflower, melons, celery, iceberg lettuce, peanuts, and artichokes (sources: MSU and University of Illinois Extensions).

Buy disease-resistant plants when possible. Check labels when shopping. "Disease-resistant varieties are denoted with a capital letter on the seed packet or in the seed catalog. For example, a VW means the tomato variety is resistant to verticillium wilt" (source: MSU).

Keep in mind that "easy to grow" can also depend on your region. For example, hot-weather-loving peppers are happier in warmer climates and grumpier in cooler areas like Seattle. Refer to your local county or university cooperative extensions for information specific to your area.

Need more help deciding what to grow? This well-produced resource from the Utah State University Extension has nutrition, planting and growing information on many fruits, vegetables and herbs (note that the planting dates are Utah-specific). Or check out this vegetable growing guide from the Cornell Cooperative Extension.

Plant flowers to attract the good bugs

Make sure your crops get pollinated. Mix some flowers in with your vegetables for bees and other pollinators. They'll add color and you'll have pretty bouquets.

Design and materials for raised garden beds

twig basketweave raised garden beds

A raised bed garden can simply be mounded earth, but experts at the Cornell University Extension recommend framed beds. A frame prevents soil erosion and helps maintain moisture levels.

Size

wood raised garden bed with ledge

Of course, the frame's overall size should fit your site. Most experts recommend 10- to 12-inch heights. Make sure you can reach the bed's center from both sides - then you won't have to step into the garden to tend it.

If you suffer from back pain, use an elevated planter with legs or with taller sides and a raised bottom, so you can garden while standing or sitting. If your planter is very deep and you want to reduce the amount of soil you need to fill it, you can do a couple things. You can raise the bottom to a depth of 12-20 inches. Or put empty plant pots or used water bottles in the bottoms of deep planters.

For wheelchair users, the University of Minnesota Extension recommends a working height of at least 27 inches. Maximum height should be 36 inches, but really it depends on what's comfortable for the gardener.

Open frames are best for worm poop

With an open bottom, water can drain, roots can grow deeper, and, best of all, our friends the earthworms can come and poop in the soil. Kentucky vegetable farmer Jesse Frost explains why worm poop (aka "castings") is so good for gardens: "Worm castings are loaded with tons of beneficial microorganisms but also many micro- and macro-nutrients that plants need to thrive. The castings improve soil structure and help the soil to more evenly distribute water. They protect from plant pathogens."

When do you need a bottom?

Your raised bed will need a bottom if you install it on a hard surface like concrete or wood, or if it's an elevated container, or being installed on top of toxic soil.

Toxic soil? Put a barrier on the bottom

Both lead and black walnut trees can poison your soil and your plants. Because plant roots can grow into the tainted ground, your raised garden should have landscape fabric or a solid bottom. You could have problems even if the walnut tree is in your neighbor's yard. The juglone given off by black walnut trees is also in their roots and can reach plants outside the tree's drip line - extending "a distance about equal to the height of the tree," says the MSU Extension. Don't line the bottom with plastic - water won't be able to drain.

Make sure the bottom has drainage holes. These will keep soil from getting waterlogged. The Sedgwick County Extension explains why drainage is so important: "Plant roots need oxygen as much as we do, and if the soil is full of water, there is no space for air! Water can smother the roots."

Contrary to popular belief, putting rocks in the bottom to improve drainage isn't a good idea. In her book Container Gardening Complete, Jessica Walliser says, "adding bulky materials to the bottom of the pot only serves to raise the water table inside the container, which floods the roots even more quickly."

Materials

Build your raised bed with wood, stone, bricks, concrete blocks, plastic tubs, metal stock tanks, retaining wall pavers, traction sand bags sold in tubes, even straw bales. Too busy to design and build? Buy a kit. You can find kits made of wood, metal, and vinyl (like our white vinyl kit).

Metal

Metal frames and containers can look great. Just be prepared to water more often. Expert gardener Joe Lamp'l tells us "metal will absorb and reflect heat from the sun – more than other materials. As a result, your soil will tend to dry out more quickly, and foliage in the line of that reflective power might suffer." If you use metal, plan to water more often and put plants that like it hotter and drier in the spots that receive reflected heat.

Galvanized metal

horses drinking from metal stock tank

When steel is galvanized, it gets a protective zinc coating to prevent rust. Some gardeners worry that the zinc or cadmium (which can also be in galvanized metal) could get into the soil. I didn't find research confirming this. In a 1982 study, researchers grew lettuce and radishes in soil samples contaminated with zinc and cadmium and found no evidence of toxicity (Roger Jones, Trent University, Canada).

An expert at the United States Cooperative Extension points out that farm animals have drunk from galvanized stock tanks for years. And, if plants did absorb zinc or cadmium, "it will most likely be in very small amounts and the plants themselves will show toxicity if the amounts are too large." To be on the safe side, avoid using rusted galvanized containers.

Straw bales

straw bale

You can grow plants in straw bales, although the bales will probably break down after one growing season. The Oregon State University Extension advises using broken-down bales for mulch or compost. One warning: make sure your bales haven't been sprayed with weed killer! 

Wood

raised garden with tomato cages

Wood is readily available at home stores and lumberyards. Use pressure-treated or "naturally decay-resistant wood such as eastern or western red cedar, northern white cedar, Osage orange, white oak, locust, or redwood." (University of Illinois Extension.)

Can I use pressure-treated wood for a raised garden bed?

This question pops up frequently in gardening discussions. With its resistance to decay, pressure-treated wood seems like an ideal material for framing a garden, since it'll last longer than untreated wood. So what's the issue?

People are concerned the preservatives used to treat wood could end up in their vegetables and herbs. Here are a couple things to keep in mind. First, all these preservatives have undergone review by the EPA and have been approved for wood treatment. The most common preservative - MCA (micronized copper azole) - approved by the EPA for residential use contains copper particles and small amounts of another fungicide, an azole. According to the University of Illinois Extension, plenty of research on the safety of treated wood in gardens has been done, "and the new treated lumbers have shown to be safe for garden use."

Second, most of the preservatives stay in the wood. Studies, such as this one, have shown that elements like copper don't travel from soil to wood to plant in any meaningful way. Furthermore, when trace elements like copper "are added to soil, most of what is added is not available for plant uptake." The elements are strongly bound to soil particles, especially clay and organic matter, according to the Penn State University Extension.

However, if you still have doubts, line the sides of the bed with polyethylene plastic.

Creosote-treated railroad ties aren't advised for gardens. Creosote is an industrial wood preservative that the EPA has “not approved to treat wood for residential use, including landscaping timbers or garden borders."

Tires

Old tires probably aren't good plant containers. "As tires wear, they give off minute, dust-like rubber particles containing cadmium that easily disperse and accumulate in soils and on plants." (Donald R. Hodel and Andrew C. Chang, University of California Cooperative Extension)

Recycled materials: Proceed with caution

Reusing materials to build a raised bed is perfectly fine, as long as you know where the materials lived before they made it to your garden. A container gardening guide written by John W. Vick and Joshua Poe, published by the University of Louisville, warns that some recycled materials (including concrete, bricks, lumber, rocks) could be toxic if they were "salvaged from a structure that may have been located on a contaminated site (such as a gas station, industrial site, etc.) or...from an older building that may have been painted with lead paint or insulated with asbestos at one time."

Vertical supports

squash plants growing on trellis

Plants that climb (such as peas) or have heavy fruit (such as tomatoes) need supports like stakes, cages or a trellis so they don't flop all over the place. Staking also improves air movement through the garden. Make sure your supports are tall and sturdy enough to support mature vegetables or fruit.

Here are some plant support suggestions from Rebecca Krans, Michigan State University Extension:

  • Tomatoes - 1-2 main stems per 5-6 ft. stake
  • Pole beans - 6-7 ft. supports
  • Clinging veggies (peas, cucumbers) - 5-6 ft. high chicken wire
  • Heavy melons and winter squash - strong structures and slings to support heavy fruits

What kind of soil is best?

Say no to plain ol' dirt, say yes to soil mixes

Filling your raised bed with earth straight from the ground will cause problems. The Cornell Cooperative Extension explains that ordinary garden or topsoil "tend to crust over, settle, and shrink away from the frames." Heavy rainfall can also compact plain garden dirt, especially if it contains a lot of clay, keeping water and nutrients from reaching plant roots. 

A better way is to mix in organic matter, like compost, well-rotted manure or peat moss. This improves drainage, adding nutrients at the same time. The University of Illinois Extension advises using “at least 1/3 existing soil in the soil mixture."

When to go soilless

If you're growing plants in a container, use a soilless growing mix. These mixes are cleaner and lighter than mixes containing soil. Also go soilless if you're gardening on a wooden deck, balcony, or rooftop.

Soil recipes

Here are two recipes for making your own soil mix. One uses soil; the other is soilless.

From Cornell:

  • 1 part organic matter (peat moss, compost)
  • 1 part sand or perlite (for drainage)
  • 2 parts soil

From Mel Bartholomew, via The Food Project:

  • 1/3 compost
  • 1/3 peat moss
  • 1/3 vermiculite or perlite

Compost is awesome, except when it kills your plants

If you don't make your own compost, you can find it at garden centers and other facilities. Know that some compost can contain herbicides that don't easily break down. This "killer compost" can stunt and ruin your herbs and vegetables. Persistent herbicides can be present in compost made from farm manure, golf-course grass clippings, even your own lawn, if you've applied weed killer. Bottom line? Know where your compost came from!

Bagged soils

When buying commercial mixes, look for those that contain a blend of organic material, not solely top soil. The Illinois Extension points out that some products labeled top soil “tend to be largely sedge peat. While they are inexpensive and look very good, once put into a pot they are poorly drained and poorly aerated." However, you can mix this peat with other soilless products or compost.

Container gardening? Avoid these potting soils

Container-grown plants are pickier about their dirt. Jessica Walliser advises gardeners to stay away from these types of potting soils:

  • Very heavy bags, especially for gardens on balconies and decks. The mix is likely "too dense for good container performance."
  • Mixes that contain soil - they "may contain weed seeds or plant pathogens."
  • Stinky mixes.
  • Bags "that contain sprouting seeds, moss, or mold."

How many bags do you need?

Soil mixes are usually sold in 3-cubic-foot bags. The University of Illinois offers this formula for figuring out how many bags to get:

Multiply length x width x height of your raised bed (in feet, not inches). Then divide by 3.
For example: 4 ft. x 8 ft. x 1 ft. = 32. You'll need 32 cubic feet of soil, which means about 11 bags of soil.

Prepping and planting your raised bed

Preparation

If you dump soil on top of grass or weeds, they could continue to grow up into your garden. But removing sod and weeds is a lot of work. I recommend the lazy gardener no-dig method.

What’s that, you ask? Lay down cardboard or several sheets of newspaper, top with compost, then add your soil mix. The vegetation smothers and breaks down, fertilizing the soil. If you have time, do this a month or more in advance.

Planting: seeds or transplants?

seedlings in paper pots
Photo by Christian Joudrey on Unsplash

Seed catalogs give you so many choices, while garden centers have vegetables already growing and ready to be transplanted. Which should you plant? The answer is both. Some vegetables take longer to mature, and you'll have better results if they get a head start as transplants. Here are some recs from the University of Illinois Extension:

Best planted as seeds: Leafy vegetables, beets, peas, greens, carrots, radish, snap beans, sweet corn, squash, turnips, and cucumbers.

Transplant these: tomatoes, peppers, eggplant, broccoli, cauliflower, cabbage, onion (sets), rhubarb, asparagus, sweet potatoes and herbs.

Tips for starting seeds indoors

Buying potted plants for your garden gets expensive. You can save money - and have more options - by growing your own transplants from seed.

You'll need a sunny window or grow lights, sterile soilless potting mix and clean pots. You can sterilize and reuse pots from last year's garden, buy new, or recycle things like yogurt cups and milk cartons. Get more information from the Seed Savers Exchange.

Seeds need to be started several weeks in advance of planting time. This seed-starting calculator and chart from Margaret Roach tells you when to start seeds indoors and when to plant seeds and transplants outdoors.

When to plant your raised garden

Some vegetables can be planted in early spring, while the weather is still cool. Others need to wait until after the threat of frost has passed. Check labels and seed packets for recommended planting dates. Not sure of your final spring frost date? Check with your local university extension.

Take your soil’s temperature before planting. The temperature affects how well seeds and transplants will grow. Some seeds refuse to germinate in cold soil - they'll just lie there and rot, like that leftover sushi you forgot in your car.

Extreme soil temperatures can destroy fine roots on young plants, hindering growth. Fresh transplants can be killed by "hot or cold surface soils," according to Linda Chalker-Scott in an article for the Journal of Environmental Horticulture. You can find soil thermometers at garden centers in a wide price range.

Kym Pokomy of the Oregon State University Extension lists soil temps that are best for planting seeds of several vegetables:

Cool soil, down to 40 degrees: arugula, fava beans, kale, lettuce, pak choi, parsnips, peas, radicchio, radishes and spinach seed 
Above 50 degrees: Chinese cabbage, leeks, onions, Swiss chard, turnips 
60 degrees: beans, beets, broccoli, Brussels sprouts, cabbage, carrots, cauliflower 
Above 70 degrees: tomatoes, eggplants, peppers, cucumbers, squash, corn, melons

Grow more vegetables with succession planting

With succession planting, you can keep the crops coming from early spring to late fall. Some vegetables grow best in cool spring weather and fade in summer's heat. Replace them with vegetables that like it hot. After harvesting in late summer, replant with more cool-season vegetables.

Cool-season crop examples (University of Illinois & Michigan State University Extensions)

  • Lettuce
  • Peas
  • Kale
  • Swiss chard
  • Radishes
  • Spinach
Warm-season crop examples
  • Beans
  • Tomatoes
  • Peppers
  • Summer squash
  • Carrots

Get a head start on the growing season

raised garden beds with row covers

With a raised bed, you can do a couple things to give your outdoor garden a head start. Soil in a raised bed typically warms up faster than ground soil. You can speed the process by laying sheets of plastic on the bed for a week or more. After planting cold-sensitive plants, cover them with "a cloche, fabric or cold frame," says Pokomy.

A cold frame is "a shallow, unheated box with a transparent cover," Beth Berlin, an educator with the University of Minnesota Extension, explains. Plants in a cold frame can bask in the sun's heat and still be protected from cold.

You can build a cold frame right over your bed. Learn how with this guide: How to Build Your Own Raised-Bed Cloche (cold frame) by Sam D. Angima and Bill Biernacki of Oregon State University.

Transplanting tips

Allow a week to harden off plants. Greenhouse- or home-grown plants need to be acclimated to the outdoors. Sudden and consistent exposure to sun and wind can weaken them. Toughen up those babies by gradually leaving them outside for longer and longer periods.

Don't transplant during the hottest part of the day. Being transplanted is stressful. Your plants will be less stressed if you transplant on a cloudy day, in early morning or late afternoon. You can also shade new transplants with a lightweight row cover.

Free the roots. Gently loosen roots if they’re circling the soil ball. If roots are matted on the bottom, break them apart.

Nip the buds. Removing flowers lets the plant put all its energy into growing roots, which is "essential with transplanting, according to the MSU Extension." This will result in more flowering and a better harvest.

Protect from frost. Can't it just stay warm for a minute? If frost is predicted, cover your seedlings.

Garden layout

planting a raised garden bed

Keep tall vegetables from shading out the shorter ones by locating them on the north or west end of your bed (University of Illinois Extension). Trellises will also create shade, and Cornell recommends installing them on the northern end of your bed. Position tall plants "just south of the trellis."

When spacing plants, follow seed and plant labels. With a raised garden bed, you don't need to make room for a path, so you can space rows closer together. But no cramming! Air needs to circulate around plants. This helps prevent diseases and fungal spores from developing.

Here are recommended seed and plant spacing tips from Michigan State University Extension:

  • Radishes - 1 inch
  • Onions, beets, carrots - 2-3 inches
  • Leeks, turnips, peas - 3-4 inches
  • Lettuce, bush beans - 4-6 inches
  • Cabbage, broccoli, cauliflower - 18 inches
  • Eggplant - 18-24 inches
  • Tomatoes - 18-24 inches

Caring for your garden

Mulch your plants

cabbage plants in mulched garden
Photo by Arnaldo Aldana on Unsplash

Mulching your plants will help your crops thrive. Mulch is a layer of organic (plant matter, compost) or inorganic (gravel, stones, plastic, textile, paper) material that covers the soil around plants. Mulch conserves water, keeps out weeds, stops pathogens in soil from splashing onto plants, maintains an even soil temperature, and prevents soil erosion.

Best types of mulch for vegetable gardens

Research has shown that the best mulch for a vegetable garden is a fast-decomposing organic mulch (made from plant matter or compost), according to Linda Chalker-Scott.

Mulching tips

Mulch with fast-decomposing organic materials. Use mulch that breaks down at rapid to moderate rates, such as grass clippings, chopped leaves, compost, hay and straw. Bark and wood chips decompose slowly and can slow the growth of vegetables and annual herbs and flowers. A study comparing basil grown in different mulches found that basil grown in hardwood and pine bark mulches had the lowest yields, even lower than unmulched basil.

Keep it loose. The ideal mulch is loose enough to allow water and air to get into the soil (Colorado State University Extension). 2-4 inches deep. The University of Minnesota Extension says "mulch that is 2-4 inches deep is sufficient for blocking out light that causes weed seeds to germinate. Deeper mulch can keep the soil too moist, reducing oxygen roots need for survival. On the other hand, Chalker-Scott cites research showing that mulch layers 3 inches deep or less failed at stopping weeds. I recommend beginning with a shallow layer of mulch and adding more if weeds invade.

Black-and-white newspaper pages are a good base for a shallower mulch layer, and water can easily penetrate the paper. Use 2-4 layers and top with organic mulch. Don't worry about lead in the ink: "printers no longer use lead compounds in ink for black and white newsprint" (Virginia Tech Extension).

Undesirable mulches

Avoid plastics - they can raise soil temps and block water and air. They don't break down and can only be used for a single year (MSU Extension). Furthermore, Chalker-Scott cites studies showing that plastic and landscape fabrics aren't good for long-term weed control.

Avoid woody mulch made from construction or demolition debris - it could contain metals or formaldehyde and harm plants (Chalker-Scott).

Don't mulch with walnut wood or bark.

Grass clippings are a good mulch for vegetable gardens, but do not use them if you've treated your lawn with herbicides or a fertilizer + herbicide blend (Virginia Tech).

Feeding

If your garden bed has rich soil, you probably won't need fertilizer. As Rebecca Krans of the MSU Extension advises, "feed the soil to feed your plants." So focus on keeping soil healthy by top-dressing with compost throughout the season. Or top-dress with rabbit droppings.

Want to be sure about your soil? Get a soil test and fertilize if needed. Krans advises applying fertilizer exactly as the manufacturer specifies. Over-fertilization can cause more problems, according to Jessica Walliser: the "succulent, tender foliage is more susceptible to certain types of fungal attacks."

Watering

vegetable garden being watered
Photo by Marcus Spiske on Unsplash

Because the soil in a raised bed gets warmer than the ground, it can dry out faster. Your bed may sometimes need daily watering, depending on the weather.

Watering tips (from the Cornell Cooperative Extension of Suffolk County):

  • Deep, infrequent watering is best for healthy plants. Mulch the bed to retain water.
  • Avoid overhead watering - it can encourage fungal diseases.
  • Concentrate on watering at the root zone, where plants absorb water.
  • Soaker hoses and drip irrigation "can reduce watering needs by up to half."
  • Water in the morning if you can - it's cooler and "evaporation is lower."
  • Recycle water from cooking pasta, washing vegetables, etc. Save it in a bucket for your garden.

Soaker hoses & drip irrigation

For ultimate convenience, use soaker hoses (easy) or a drip irrigation system (more complex) with a timer. A soaker hose is laid on top of the soil around plant rows and connected to a regular hose. A drip irrigation system has more components. Both systems conserve water use and apply water directly to plant roots, where it's needed.

Capture rainwater with a rain barrel

Save money and conserve water by capturing rainwater with a rain barrel. Terry Gibb, Michigan State University Extension, explains: "A rain barrel is a large container with a top that a home’s downspout fits into and a spigot at the bottom to get the water out for use...[rainwater] contains no chlorine, lime or calcium which makes it beneficial for gardens." If you want to install a rain barrel, here are instructions from the Rutgers Agricultural Experiment Station.

Keep beds clean

Remove detritus, weed seedlings, and diseased or dead plant matter. If a walnut tree's nearby, be sure to remove any fallen walnut leaves, hulls and seedlings.

Dealing with garden pests & disease

Critter control

chipmunk on raised garden
Photo by Tony Fortunato on Unsplash

Snow White, you aren’t welcome in my garden because your ravenous vegetarian forest animal friends are rude. We have ways to deal with these creatures.

The lazy and safe way to keep deer and other critters out of your garden is to use lightweight plastic netting. The netting comes in rolls and is usually black or dark green - practically invisible from even a small distance. You can cut it with scissors. Just toss it over plants in the early evening and remove it in the morning - it only takes a minute. And it's reusable for years. I followed this practice to stop deer from stripping my hydrangea bushes - it worked perfectly.

Another option involving more effort: deer avoid "small, penned-in sites," advise Beth Jarvis and David Bavero of the University of Minnesota Extension. They suggest enclosing your raised bed with a 4-foot-high fence or a snow fence to keep away claustrophobic deer.

Deer repellents: They're meant to repel deer via a terrible taste or smell. But effectiveness is iffy. Jarvis and Bavero reported that a Connecticut study testing 6 repellents found that effectiveness ranged from 15% to 46%.

Tunneling rodents: Some critters, like gophers, will sneak underneath your garden to eat root vegetables. Block them by placing hardware cloth on the bottom of your raised bed.

Mothballs: nope. Some gardeners use mothballs to control squirrels and other rodents. Gardening expert Margaret Roach warns against this. Mothballs are a pesticide. "The label of any pesticide, including mothballs, specifies exactly where and how you can legally use the product. Using mothballs in a way not specified by the label is not only illegal, but can harm people, pets or the environment," Roach says.

Insect control

bee on lavender
Photo by Aaron Burden on Unsplash

Some insects will attack your plants, others will attack the attackers or pollinate your plants, and knowing who’s who is hard. This infographic lists some of the good guys.

Remember this about pesticides - they will destroy all the bugs - even the good ones. And what about birds that eat the poisoned bugs?

To be on the safe side, don't put pesticides on your plants. I find knocking the evil insects and caterpillars into a cup of soapy water very effective. But don't drop them into your coffee cup because you might accidentally take a sip, speaking from experience.

If slugs are a problem, kill them kindly by setting shallow dishes of stale beer outside your raised bed. They love it and don't mind if the hop-malt balance is off.

An effective non-toxic way to control adult insects is placing row covers over your garden in spring right after planting. Just "be sure to remove the cover when flowers appear as bees and other pollinators will need to get to the flowers to pollinate," says Rebecca Krans.

If bugs are blitzing your crops and you need more ammunition, experts who study insects recommend protecting pollinators and beneficial insects by using low-impact pesticides such as insecticidal soaps, horticultural oils and biopesticides.

To identify bugs, check out this excellent pest identification guide from the West Virginia University Extension.

Plant diseases

Disease is an ongoing concern for gardeners. Plants can catch diseases from soil and via wind, water or insects, according to Jessica Walliser. Symptoms include spots, discolored or powdery patches, and wilting.

To help prevent disease, follow Walliser's tips:

  • Plant disease-resistant varieties
  • Allow space for air to circulate
  • Water in the morning, and water at the roots
  • Remove and destroy infected leaves
  • Clean your garden tools
  • Don't over-fertilize
For help figuring out what's wrong with your plants, check out the University of Minnesota Extension’s diagnostic  guide.

Harvesting your crops & saving seeds

red tomatoes with stems
Photo by Andrea Riezzo on Unsplash

Pick vegetables as soon as they mature. The more you pick, the more plants will produce. Morning is the best time to harvest, "ideally before 10:00 a.m., when the weather is still cool and water content within the plants is still high," says Jessica Walliser. And refrigerate your haul right away.

Handle veggies carefully while harvesting - nicks and bruises may spoil them faster. Most produce should be stored in cold (32-40 degrees F.), moist environments. Perforated plastic bags are better than unperforated bags, which develop condensation that leads to mold (University of Minnesota).

Need recipe ideas for enjoying your harvest? let me recommend my favorite vegetable-centered cookbook, " The Love and Lemons Cookbook," by Jeanine Donofrio and Jack Mathews.

Harvesting herbs

Walliser recommends regularly harvesting herbs "to encourage more growth and to keep them from going to flower." Snip the flowers off herbs that you grow for the leaves, such as basil and oregano. Once the flowers set seed, the plant will think it’s done.

Preserving your harvest

Your garden will be so prolific, you'll have more produce than you and your friends can eat in a week. Preserve the extra by freezing, dehydrating, canning, and pickling. University extensions have plenty of information to guide you, like this food preservation resource page from the University of Minnesota Extension and Choosing, Storing & Using Fresh Produce from the University of Maine Cooperative Extension.

Protect your crops from frost

Most plants will keep producing well into fall if the days are warm. Protect tender plants (beans, cucumbers, summer squash, peppers, tomatoes) from chilly nighttime temperatures by covering them at night. Some vegetables - cabbage, kale, broccoli, Brussels sprouts, carrots, turnips, cauliflower - will chug through several frosts, but pick them before temps reach 20 degrees F. (Kansas State Extension).

Saving seeds

sunflower against sky
Photo by Loren Joseph on Unsplash

You can save money by saving seeds to plant next year. You can do this if your plants were pollinated naturally and aren't hybrids, says Gretchen Voyle of the MSU Extension. To know if a plant is a hybrid, check the plant label or seed package. "Hybrid vegetable plants are products of crosses between two different varieties, combining traits of the parent plants," says Jill MacKensie of the University of Minnesota Extension. Plants grown from their seeds won't be exactly like the hybrid plant.

How to harvest and store seed

To save seed from vegetables and fruits, let fruit ripen on plant. Then remove seeds and let them dry in a single layer, says Voyle. From seed pods and flowers, keep pods and dead flowers on plants until they dry, then shake into a container.

Voyle recommends storing dry seeds in paper envelopes or bags. You can also store them in glass jars - keeping them dry is important for preventing mold. And don't forget to label!

Keep a garden journal

One final thing. Take photos of your garden all season long - the good and the ugly. This visual reminder will be a huge help as you plan next year's garden. List your plants and what happened to them. If you found that six basil varieties were four too many, you'll want to remember that next spring. And share your experience. We’d love to hear about your gardening adventures!

How can I find my local cooperative extension service?

A fantastic resource for gardeners, cooperative extensions are affiliated with more than 100 land-grant colleges and universities. They provide a wealth of research-based information on gardening, farming, nutrition, food preservation and many other topics. Some extension websites are better than others, so browse patiently :)

To find your local extension, check out this list of cooperative extension websites.

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