Vegetable, Fruit, and Herb Gardening in March
March is one of the very busiest times of the year in our garden. We are turning over the soil to expose overwintering pests, redesigning beds to make use of good crop rotation practices, and getting early spring food vegetables in the ground. It is a family tradition to get potatoes in the ground by St.Patrick’s Day. Peas are already popping their heads up ready to be covered with hay at the first sign of a hard snow or deep freeze, which is always possible with our unpredictable Oklahoma weather! The month of March is the transition from winter to spring and highly enjoyed!
- Sow seeds indoors for the following vegetables: broccoli, cabbage, cauliflower, celery, eggplant and head lettuce.
- On nice days, go outside and turn the compost pile. This will get it “cooking” again. It will also help you resist the urge to start working the soil too soon.
- Coriander seeds make fragrant additions to potpourri. To grow coriander, sow seeds directly into beds as soon as the danger of frost has passed. The planting should be located in full sun to partial shade in well-drained soil. Do not over fertilize coriander, as high nitrogen will result in plants with decreased flavor.
- Parsley is rich in vitamins A and C. Start some seed indoors now for later transplanting to a sunny corner of the vegetable garden.
- Tops of onions seeded last month should be clipped to keep them at about 4 inches. This diverts energy to bulb growth.
- Pick a permanent spot for herbs in the garden. Many of them will come up year after year.
- A good, salt substitute for anyone who wants to restrict sodium intake is a blend of equal parts dried basil, dill, lemon balm, marjoram, mint, parsley, rosemary, thyme and a few dashes of Hungarian paprika. The mixture will keep indefinitely in a dark glass or ceramic container.
Gardening Tools and Equipment – March
- Protect yourself and the blade of your pruning saw during storage. Make a cover for it using a piece of old garden hose the same length as the blade. Cut the hose lengthwise on one side, and place it over the saw blade.
- A 5-gallon bucket, already a popular garden carry-all, can be converted into a dual-purpose, tool holder/harvest bucket by tying a tool pouch to the outside. Outside the bucket, carry trowels, pruner and seeds. Inside, collect vegetables or weeds.
- Ice cream scoops are great for digging holes for transplants; the dirt slides off easily.
- During inclement weather, clean and sharpen garden tools and prepare other gardening equipment for the busy months ahead. Inventory pesticides, fertilizers, bags of potting soil and amendments. Finish up last year’s records. There’s still time to do a little dreaming and planning.
- If you haven’t done it already, check stored tools and outdoor furniture for signs of rust. Remove any surface rust with steel wool, and paint with rust-inhibitive paint.
- If your tiller turns over sluggishly in spring, before trying to start it, move it to a sunny location and cover it with a black plastic garbage bag for half an hour. A few minutes of solar heating will warm up the fluids and make starting easier.
Trees and Shrubs – March
- Flowering shrubs may be moved at this time. Larger shrubs should be moved with a ball of dirt and smaller shrubs may be moved bare-rooted.
- A good rule of thumb for planting rhododendrons is: the smaller the leaf (i.e., R. carolinianum, R. laetivirens), the more tolerant it is of winter sunlight. Large-leaved rhododendrons, such as R. catawbiense or R. maximum, have more winter injury when planted in bright locations.
- When transplanting a young shade tree, it may help to orient the tree in its new location the same way it was in its old home. This will prevent previously shaded bark from suddenly being exposed to afternoon sun and causing injury. When not possible or desirable, or if the original orientation is unknown, wrap the trunk in tree tape or coat the sunny sides with white, exterior, latex paint for one growing season.
- Be aware that a brown plastic material that looks and feels like natural burlap, but does not break down in the soil, is now being used to wrap root balls of balled and burlapped plants. Synthetic materials enclosing the roots of trees and shrubs must be completely removed to ensure success of the transplants. Nurserymen have being alerted to avoid using brown plastic burlap, but there are still some landscaping plants on the market with soil balls wrapped in brown plastic. If you purchase balled and burlapped plants, to be on the safe side, remove the material covering the soil. If the tree is very heavy, peel the burlap down to the bottom of the hole if you cannot remove it completely.
- Some towns and cities are repeatedly bothered by inexperienced people selling trees or shrubs that have been dug from pastures or forests. Such plants usually have poor survival rates due to small, shallow, root systems that may have been damaged when dug or stored improperly. The best trees and shrubs are those grown in a nursery where a deep, full, root system develops. When these are carefully dug and the roots kept moist, the plants should recover quickly after transplanting.
- If you are buying bare-root trees, look for ones with a large root system in relation to the top growth. It is not necessary to purchase a very, large tree to get a quality plant.
- Potted azaleas, available through May, will flower for two to three weeks, if the soil is kept slightly moist. Display in a cool (60° F), bright location, and remove withered flowers. Unless you have room to experiment, discard when blooms fade since most florist azaleas are not hardy enough to be established outdoors.
- Young trees can be inexpensively protected from rodents, string trimmers and mowers with short, plastic, tube-shaped, tree guards. Each protector should be 9 to 10 inches tall and long enough to wrap around the entire trunk base. At least one company sells trimmer guards for trees, but gardeners can cut other plastic tree protectors to size for this purpose.
- Add compost to trees and shrubs with weak growth to stimulate more attractive development.
- Research has shown that young trees allowed to move with the wind develop greater trunk strength than trees rigidly staked.
- Plant roses and bare-root shrubs while they are still dormant, about four weeks before the average date of the last frost.
- Crab apples, valued for their beautiful spring blossoms and attractive fruit, are members of the rose family. Along with their relatives, many crab apples are susceptible to
diseases, such as scab, cedar-apple rust, powdery mildew and fire blight. All of these diseases shorten the life span of the trees and diminish their ornamental qualities.
Plant disease-resistant cultivars of crab apple, such as ‘Ames White,’ ‘Autumn Glory,’ ‘Baskatong,’ ‘Beauty,’ ‘Coral Cascade,’ ‘Evelyn,’ ‘Harvest Gold,’ ‘Molten Lava,’ ‘Red Snow,’
‘Robinson,’ ‘Tina’ or ‘Wies.’
- Dogwoods and magnolias should only be moved in early spring. Always move magnolias with a ball of dirt.
- Propagate deciduous shrubs, such as forsythia and winterjasmine, now by ground layering.
- When transplanting dogwoods, it is best that the trees be small (2 to 3 feet tall) and dormant. These do better than larger ones. The larger the tree, the greater the risk
of death due to transplant shock since more roots are removed during digging.
- Boxwoods may be moved now; do not plant them deeper than they were previously planted. Trim and add compost established boxwoods before new growth starts,
but do not cultivate under boxwoods since their roots are shallow and may be damaged.
- Some insect pests of trees and shrubs are best controlled by spraying with dormant oil. This includes scale insects of pine, lilac and euonymus and many of the gall-forming insects. These insects reside on stems or needles and are smothered by the oil.
- Galls are mostly a cosmetic problem, but scales can weaken plants. Check weather forecasts to be sure temperatures will stay above freezing for eight to 12 hours after spraying to avoid damaging stems and needles.
- Be sure to employ properly trained tree trimmers. Pruning is not a particularly difficult job. However, it does require an understanding of the growth habit of the plants and the form needed to secure the desired landscape effect.
- Once new growth begins on trees and shrubs, cut back winter-killed twigs to living, green wood.
- For more compact pyracanthas without the risk of losing berries, pinch back new growth now.
- Prune evergreens and evergreen shrubs for shape and size before growth starts, as early in the month as possible
- Boxwood should be pruned by thinning the outer foliage of the plant and cutting back the branches to retain desired height.
- Prune spring-flowering shrubs after flowering is completed.
- Hedges can receive their first pruning this month. As you prune, be sure to leave the base of the plant wider than the top. This allows sunlight to get to the bottom of the plant, creating a full, dense hedge.
- Don’t leave stubs when pruning; stubs usually die and are entry points for decay fungus. Cut just outside the branch collar, the slightly thickened area at the base of the branch. Pruning should never be done in damp or wet weather when the fungal spores and bacteria that infect plants through fresh wounds spread easily.
- Trees that bleed, such as birch and maple, should not be pruned until after their leaves are fully developed. Elm, maple, birch and black walnut trees ooze sap when pruned
in the spring due to water pressure from the moist soil. It will not harm the plant, but you can prune these in early summer or late fall instead if you are bothered by it.
- After pussy willow catkins have passed their prime, prune the plants drastically to encourage long branches and large catkins for next year.
- Plant new rose bushes in properly dug beds. Add compost to established roses after pruning. It is wise to have your soil tested about every two years. If black spot or powdery mildew has been a problem, start applications of a recommended fungicide. Contact your local Extension agent for current recommendations.
- When pruning or cutting roses, cut all flower stems 1/4 inch above a complete (5 leaflet) leaf, leaving two complete leaves below the cut bud. Always use sharp, pruning shears and cut on a slant.
- Complete the pruning of shrubs and ornamental trees before new growth starts, except for spring-flowering shrubs. Prune those in the spring after they finish flowering.
- For good drainage in tight clay, plant trees on the “high side” by building up the area around the root ball or by laying drain tile from the bottom of the hole to a ditch or to a special drainage area. Provide a drainage area by digging another hole lower than the planting hole and filling it with gravel. Use pipe or tile to carry
excess water to this hole from the tree roots. Another solution is to play it safe and select a tree that withstands “wet feet.”
- Spring flowering shrubs can be pruned now, too, unless you can’t stand losing the flower buds on the stems you’re removing.
- Branches cut from spring-flowering shrubs and fruit trees can be brought in and put in warm water to force them into bloom.
- Do not use tree wound dressing or paint on pruning cuts. These can slow the healing process.
- Prune out and burn or bury the brown, shriveled “witches-brooms” on honeysuckle. The leaf-folding aphid that causes these overwinters in these growths. They feed on new growth as soon as the buds break in the spring. This one is hard to control, because untreated honeysuckles are everywhere. This may be a good time to consider replacing honeysuckles with less invasive plants that have fewer pest problems.
The end of the dormant season is the best time to prune almost all trees and shrubs. Pines are about the only exception. Let their new growth expand until young needles are half of full size before pruning.
Miscellaneous March Tips
- A clipboard to which you can attach your notes while working in the garden is a helpful gardening aid. Using graph paper, map out your plot. Note the varieties and dates of planting to aid in planning successive plantings and to help determine the expected time of harvest.
- A child’s first garden should include sunflowers from seeds. The large seeds sprout quickly and dependably, and the strong seedlings can push their way through crusted soil. If you are shooting for record sunflowers, your plants will need to top 20 feet in height with seed-head diameters of 2 feet to be in the running.
- Mulches can change the soil temperature. Black plastic warms the soil and should be applied before planting. Organic materials delay the sun’s penetration thereby keeping the soil cooler. Apply organic mulches after plants are 3 to 4 inches tall and the soil is warm.
- Place bird houses outdoors early this month. Birds will begin looking for nesting sites soon, and the houses should attract several mating pairs. Ideally, houses erected on smooth metal poles where predators cannot climb are most often selected, but placement on top of fence posts or in trees will usually suffice.
- An apple a day may keep the doctor away, but two carrots a day can cut cholesterol levels by 10 to 20 percent, say USDA scientists. Carrots, as well as cabbage and onions, contain a type of fiber that lowers cholesterol.
- The most common nematodes are saprophytes that feed on decaying organic matter. They play a critical role in maintaining the balance of nature and in returning nutrients to the soil.
- Don’t overexert those under-worked, winter muscles as you begin your spring gardening. Bend at the knees and lift with your legs, not your back!