The blustery winds and fluctuating temperatures of March can do damage to northern gardens. There is a tendency, when the weather is fine, to uncover plants protected all winter. This could lead to disaster.
Tender growth suddenly exposed to frosty winds will shrivel. If there is heavy covering, remove only a part of it, allowing the new growth to become acclimated to full exposure gradually.
This applies to perennials, bulbs, and similar plants. In the more favored sections of the Northern area, some covering can be removed from roses preparatory to pruning.
Broad-leaved Evergreens
This is the season when the broad-leaved evergreens suffer most from constant winds. Keep a mulch over the roots and, if the necessity arises, supply water.
The greatest danger is to those plants with roots in a frozen soil. The roots cannot supply moisture fast enough to replace that pulled out by the winds. Burning and shriveling of the foilage results. In extremely exposed sites, use a windbreak for a week or two.
Spring Soil Improvements
When frost has left the ground, you may begin digging and preparing the soil, provided the soil is not wet. (Try the wet ball test) Nothing is gained and much can be lost by working a wet soil, especially if there is much clay in it.
Consistent with this, the earlier the soil can be dug the better. Adding organic matter is a must in all spring preparation.
Compost and manure should be well-decayed. If manure is fresh, see that it is well mixed with the soil and then delay planting or seeding for at least two weeks. Add 4 pounds of superphosphate per 100 square feet. Chicken manure is balanced with 1 pound of superphosphate to every 10 pounds of manure.
If these materials are not available, the next best organic material is a mixture of half peat moss and commercial humus. To every bushel (32 dry quarts) of this mixture add 3 pounds of superphosphate, 3 pounds of dried cattle manure and 1 pound agricultural lime. Two bushels will cover a 100-square-foot area.
Seed and Planting
If conditions permit the preparation of the soil, they are also right for sowing early seeds and setting out hardy plants. Seeds of the hardier vegetables, such as radishes, carrots, beets, spinach and onions, can be sown in drills 12” to 15” inches apart and covered with 1 1/4″ inch of fine soil.
Smooth-type peas, another early crop, need excellent soil, fertilizer, and care. Wrinkled kinds are sown later. Drills, or rows, are spaced 3’ feet apart.
The seeds are covered with an inch of soil. Hardy annuals, such as sweet peas, larkspur, Shirley poppies, cornflower, and calliopsis, are sown at this time also, and perennials, roses, shrubs, and all fruits may be planted.
Pruning
Many people ask for information on pruning blueberries. Old plants set out and over the years have become large if crowded together or growing among shrubs, cannot be expected to give results. The berries are produced on small twigs of the previous year’s growth scattered over the stems’ upper part.
If these twigs are overproduced, they must be thinned by cutting out part of the stems at the top.
Removing a few older branches to the ground may be advisable to stimulate young stems for better fruit. If the bushes are leggy and without fruiting twigs, it will be necessary to cut several main branches back two-thirds their length to force new twigs for fruiting next year.
Blueberries need very acid soil, much more acid than for rhododendrons. Soil that is neutral or slightly acid can be made more acid by mixing quantities of acid peat or leafmold with the soil.
Sawdust is useful for covering the soil with a mulch that maintains an acid condition. Two or three-year-old plants, though more expensive, are best for home planting.
The Clematis
Pruning the clematis vine gives trouble to home gardeners.
The fall-flowering clematis paniculata is pruned now by cutting the stems low, depending upon the location and the size of the structure it covers. It is a vigorous grower and hard cutting produces the best flowers.
The spring-flowering types such as Clematis montana and Clematis rubens, on the other hand, are not pruned until after flowering in June. There are many summer-flowering varieties, such as the most prevalent Clematis Jackmani and some of its hybrids, that are pruned in spring as they flower about July.
Some, however, need very little pruning beyond the removal of weak or injured growth.
The Trumpet Vine
The trumpet vine is pruned quite hard in spring, but the pruning of wisteria is confined to the cutting of the spurs that have the flowers. Unless the plants have been subjected to summer pruning, or you are experienced enough to recognize the plump buds on the twigs, better leave them alone.
The Coldframe
Coldframe management in March involves proper ventilation and watering. The interior of the frame heats up rapidly on a sunny day and could result in damage to seedlings. The sash should be lifted slightly on the side away from the wind as soon as the temperature rises towards 70° degrees Fahrenheit.
Watering, when needed, is also done on a rising temperature and by means of a mist-like spray. The sash is lowered in the afternoon while the sun is still warm in order to trap heat. Then, by covering with hay, sacking or regular coldframe mats, the heat is retained throughout the night.
The best soil for a cold frame is a mixture of 3/4 garden loam and the remainder of peat moss, sand, or screened compost. A 6” inch depth is needed for seeds and young transplants.
Another method is to have the bottom of the frame covered with ashes or sand. The seeds are then sown in flats or pots set on the sand or ash base.
Lawns
The earlier the lawn can be put in shape, the better. It may be too early to run a roller over it because of the excess moisture and danger of later packing. If the grass is thin and extra seeding is indicated, seed as soon as possible.
Seeds germinate best in the cool season, and the grass gets a chance to become established before summer. In March most lawns need a good surface dressing, with a well-balanced fertilizer.