Gardeners Checklist: Here Is What to Do on the Week of March 24

By Ron Kujawski

* Start tomato seeds indoors. I know many people like to start sooner, but research has shown that six- to eight-week-old tomato seedlings make the best transplants. Everyone has their favorites when it comes to tomato varieties. I like heirlooms such as ‘Mortgage Lifter’ or ‘Brandywine’ for eating fresh, ‘San Marzano’ for sauce and canning, and ‘Sungold’ for salads and snacking.

* Dig up the roots of horseradish. Though the roots will keep in the refrigerator for several weeks, you’ll get the most pungent sauce if you grate them soon after digging. I grate horseradish outdoors, preferably with gale-force winds at my back.

* Sow peas soon, but save some seeds for planting in mid-to-late August for a fall crop. 

* Go ahead and plant trees and shrubs. Consider native species when making choices.

* Prune hedges now, but make sure to leave the base of the hedge wider than the top. This allows sunlight to reach the low parts of the plants. The reason that many hedges have naked bottoms, that is, are leafless at the lower parts, is the lack of sun.

* Keep potted daffodils, hyacinths, and other forced bulbs growing as long as possible after they have flowered. Treat the plants as if they are houseplants by watering regularly and applying fertilizer now and then. Once the leaves begin to turn yellow, stop watering and allow the leaves to dry. Once dry, plant the bulbs outdoors in the garden.

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As mentioned in last week’s column, soil organic matter is the key to successful gardening. There are many ways of increasing soil organic matter, including incorporating compost or aged manure into soil when preparing gardens for planting. However, those who don’t have a compost pile or free access to an aged cow or horse may find it costly to purchase enough organic material for all their gardening needs. A reasonable solution to this problem, especially for vegetable gardens, is to plant cover crops. A cover crop is a grass, legume, or other plant grown as a temporary crop for the purpose of adding organic matter to soil. For example, last fall we sowed seeds of winter rye in the garden. The rye will now be tilled under and allowed to decompose, thus increasing the organic matter content of the soil. We till under the rye two weeks prior to planting. During the growing season, whenever vacant space occurs in the garden, we’ll sow seeds of a non-hardy cover crop such as berseem clover, buckwheat, or sudex grass. These can be tilled under at any stage of their development, or after they have been killed by frost in fall, or in the following spring.

Ron Kujawski began gardening at an early age on his family's onion farm in upstate New York. Although now retired, he spent most of his career teaching at the UMass Extension Service. He serves on Berkshire Botanical Garden’s Horticulture Advisory Committee. His book, Week-by-Week Vegetable Gardener’s Handbook, is available here.