I. TIPS ON TIMING
Love those early warm spells, but don’t be in a rush to plant warm season vegetables. Warmer soil temperatures are important for the success of veggies like corn, beans and squash. If the soil is too cold and wet, germination will be slow and, worst case, seed may rot. Tomatoes, peppers and eggplant are really tropicals and prefer nighttime air temperatures consistently above 50 degrees. Nighttime lows below 50 will slow, if not permanently stunt their growth, so there is really no gain in transplanting them out too early, unless you put considerable time and effort into sheltering the plants until night temperatures warm; usually with heavy use of fossil fuel based products. (If you really feel compelled to plant them out early and build plastic tents, used wall-o-waters, etc. please wash and reuse the plastic product as many seasons as possible. To ultimately recycle, the plastic needs to be relatively clean. I put one piece at a time in with a load of laundry, then off to the recycler.)
Advice on Soil Temperature from the Oregon State University Extension Service
Crops that will germinate in the coolest soils (down to 40 degrees) include arugula, fava beans, kale, lettuce, pac choi, parsnips, peas, radicchio, radish and spinach seed.
With a soil temperature above 50 degrees, Chinese cabbage, leeks, onions, Swiss chard, and turnips can be planted.
When the soil warms to 60 degrees, warm season and many cool season vegetables can be sown, including beans, beets, broccoli, Brussels sprouts, cabbage, carrots and cauliflower. But be forewarned – beans will not tolerate any frost and may have to be planted again if the temperature goes below freezing.
Wait until the soil warms to above 70 degrees to plant warm season vegetables including tomatoes, eggplants, peppers, cucumbers, squash, corn and melons. Tomatoes, eggplants and peppers are slow-growing and take many weeks to grow to the stage where you can plant them out in the garden, so you might want to purchase these as starts from your local garden center. On the other hand, squash, cucumbers and corn grow quickly and are easier to start from seed.
Deborah Kean, an Oregon State University vegetable researcher, provides these hints to ensure further success with early season vegetable gardening:
• Wait to plant until the soil reaches the proper temperature for a specific crop.
• Buy cold-tolerant or short-season varieties.
• Warm the soil with plastic mulch, a cloche, a Wall-o’-Water, spun fiber or fabric “floating” row cover or cold frame.
• Be prepared to protect things if a hard freeze is forecast. Just because a crop has germinated and is starting to grow doesn’t mean it can’t be hit by a late frost.
• Prepare well-aerated soil with plenty of organic matter for a seedbed.
By: Carol Savonen
Source: Deborah Kean
Thermometers to measure soil temperature can be purchased at well stocked nurseries, such as Portland Nursery in Portland; The Gardener’s Choice in Tigard, or ordered via mail from Territorial Seed Company.
Provide adequate nutrition according to the needs of each plant. Here is a table of veggie plant neediness.
asian cucumbers, asparagus, broccoli, early brussels sprouts, early cabbage, early kohlrabi chinese cabbage, cantaloupe, cauliflower, leeks, early mustard greens, bulbing onions, large fruited peppers, spinach, early turnips
artichoke, sprouting broccoli, late brussels sprouts, late cabbage, corn, non-asian, cucumbers, eggplant, garlic, lettuce, spring onions, potatoes, pumpkin, radish, rutabaga, late spinach, squash, tomatoes, late turnips, watermelon
arugula, beans, beets, carrots, endive, escarole, fava beans, most herbs, jerusalem, artichoke, kale, parsnip, peas, swiss chard
legumes (clover, vetch, peas, soybeans)
grasses (ryegrass, wheat, oats, barley, alfalfa)
I mainly see two different brands of organic fertilizer mix in our neck of the woods: Dr. Earth and Edna’s Best, (usually $25-30 for the largest bag, which I believe is about 20 lbs) which are fine, but the out-of-pocket can be painful. It’s less expensive to make your own complete organic fertilizer and recipes abound. They need to include sources for nitrogen (N) phosphorous (P) and potassium (k), plus calcium and various other minerals and trace elements in small amount. For years I’ve used a recipe for complete organic fertilizer that originally came from Steve Solomon’s “Growing Vegetables West of the Cascades” :
4 parts seed meal
1 part dolomite lime (1/2 agricultural ½ dolomite)
½ part bone meal -or- 1 part soft rock phosphate
½ part kelp meal
However, this year when I went to pick up fertilizer ingredients at the “Concentrates” Agriculture supplier (“Organic Agriculture Since 1938”), a very knowledgeable Naomi Montacre introduced me to her own lab tested mineral mix (50 lbs @$20). Mixed ½ and ½ with linseed meal (50 lbs @$23it’ll provide my main supply of complete organic fertilizer with much less mixing and measuring. I realize this makes a large amount, so if your garden is smaller, you could go in on the items with a neighbor. This stuff will keep for quite a while, as long as you keep it dry. (FYI: Naomi recommends you apply these separately, since different plants need differently levels of certain elements, such as nitrogen.)
2613 S.E. 8th Avenue
Portland, Oregon 503-234-7501 or 1-800-388-4870
You may also be able to find some fertilizer ingredients in bulk at feed stores (if you can find a feed store). Both Portland Nursery (50th and Stark) and Pistils Nursery (3811 N. Mississippi Ave.) stock them as well. I’m not sure about the range of product, and you’ll need to make your own price comparisons.
When applying fertilizers, you’ll have more control if you choose a calm day. Too breezy and you’ll end up fertilizing your neighbor’s garden. MAKE SURE TO WEAR A MASK WHEN MIXING and isolate the process from children and pets! I am not kidding! I dump everything into my wheelbarrow and mix it up with a shovel.
III. PLANTING FOR BENEFICIALS
Include plants for beneficial insects in your garden. Like it or not, gardeners are in for some thrilling and at times aggravating lessons in entomology, the scientific study of insects. According to Wikipedia, insects account for more than two-thirds of all known organisms, so we’re bound to bump into a few!
If we’re involuntarily introduced to so many bugs, why would we want to invite more of them into our garden? Because, other than functioning as pollinators, beneficial insects are a natural biological control for pests that are after more than a fair share of our garden bounty. Insects perform numerous behind-the-scenes functions and are part of the natural order. And they can be really beautiful.
Next to planting bug resistant species of vegetables and providing ample soil fertility, beneficial insects rate highly in the practice of growing healthy vegetables “naturally.” Often, just as you think an insect is getting more than its fair share of your crop, its natural enemy appears in the form of a “beneficial” insect, reducing incidence of crop damage enough that we can “let well enough alone.
In order to enjoy this sidelight of gardening, pick up a small magnifying glass and one or two “bug books.” Get to know your insects; friends and foe.
For all you know, that “worm” you’re about to squish is the larval stage of the Western Tiger Swallowtail Butterfly!
A Few Plants Known to Attract Beneficial Insects
Alyssum (Lobularia maritima): Attracts hoverflies and parasitic mini-wasps. Benefits fade as the blooms age, so shear the flowers periodically to keep ‘em coming.
Basil (Ocimum basilicum): The flowers attract bees and other beneficials. The foliage supposedly repels aphids (of which we have many) and tomato hornworms (I haven’t seen these so far). TONS of Bees come to African Basil O. kilimandscharicum × basilicum and Thai Basil, O. basilicum var. thyrsiflorum, both stunning purple highlighted plants. Not my pick for culinary use, but I plant several Thai and African Basils around the vegetable garden and let them bloom to their heart’s content.
Cosmos: Attracts lacewings, hoverflies and parasitic mini-wasps, bees and lady-bugs. White is the best. These will self-sow and the new seedlings often bloom in the same season.
Dill (Anethum graveolens): We know this herb from use in pickles and various recipes. The umbel flowers attract lacewings, ladybugs, hoverflies and parasitic mini-wasps. Touted as a “trap crop” for aphids. Occasionally self-sows.
Love-in-a-Mist (Nigella damascena): annual with beautiful, blue flowers in early summer, followed by ornamental seed pods. The seeds are edible and can be used in fruit salads and baked goods. Nigella sativa (Black Cumin) has spicy, pepper-flavored seeds that I recently discovered are popular in Indian Cooking. Can be self-sowing.
Parsley (Petroselinum crispum): The umbel flowers attract hoverflies, tachinid flies and parasitic wasps. (Actually a biennial.) Let your parsley go to flower and you may also be rewarded with more parsley plants, a good thing since seeds can be tough to germinate. I’ve not had parsley self sow, but others claim it.
Zinnia (Zinnia elegans): use the single petal varieties for attracting hoverflies, parasitic wasps and butterflies.
Anise Hyssop (Agastache foeniculum): licorice-flavored leaves for tea. Spikes of blue flowers attract bees, butterflies and beneficial insects. Blooms the first year from seed.
Basket of Gold (Alyssum saxatile): The bright yellow flowers bloom in May, providing an early food source for ladybugs and hoverflies. The plants can get rather large and ratty looking after they blook. Just cut them to the ground when they’re done and they’ll make a neat mound of green in time and bloom again next year.
Bee Balm (Monarda citriodora): Like the name says, bees love it. The lemon or mint scented leaves are edible, and the often stunning tubular flower bracts attract butterflies and hummingbirds. May need dividing every 2-3 years to control clump size. Subject to powdery mildew. Even “resistant” varieties can get it, they’ll just survive and look kind of gross close up.)
Purple Coneflower (Echinacea purpurea): This perennial wildflower is sometimes listed as an herb because the roots are used in herbal medicine as an immune stimulant. The flowers attract bees and butterflies. These often have a scent, if you dare get your nose that close.
Sage (Salvia sp.): Many forms, loved by plant collectors. In flower, they all attract bees and butterflies, and the tubular flowers of some varieties attract hummingbirds. Many of these will self-sow. The culinary sages can be beautiful but typically don’t bloom as prolifically.
Thyme (Thymus sp.): Attracts bees, hoverflies, tachinid flies and parasitic mini-wasps.
Yarrow (Achillia filipendulina and millefolium): Attracts ladybugs, hoverflies and parasitic mini-wasps. In my experience, A. millefolium, both the species and many of the cultivars, are noticeably spreading by the third year in the ground. Don’t let it get away from you.)
OSU Master Gardener Offices:
Clackamas County: 503-655-8631 M-Th: 9am – 11:30am & 1pm – 3:30pm
Multnomah County: 503-445-4608 M-F: 10:00 am to 2 pm
Washington County: 503-821-1150 M-F: 9am -12pm & 1pm – 4pm
OSU “Pacific Northwest Management Handbook” http://uspest.org/pnw/insects
A Color Handbook of Biological Control in Plant Protection, by Neil Helyer, Kevin Brown, Nigel D. Cattkin
Insects of the Pacific Northwest, by Peter and Judy Haggard
Natural Enemies Handbook: The Illustrated Guide Biological Pest Control, by Mary Louise Flint and Steve H. Dreistadt
Pests of the Small Farm and Garden: A Growers Guide to Using Less Pesticide, by Mary Louise Flint