Southern Idaho Locations
This month is an opportune time to prune fruit trees and fruit-bearing canes such as raspberries. Shrubs and shade trees may be pruned as well. Shrubs that have spring flowers should not be trimmed until early summer, since pruning now will remove flower buds. Avoid pruning most roses until April or May, near the time of the last frost.
Trim old-fashioned rose bushes (not hybrid types or grafted varieties) beginning the last week of March. It is all right to apply dormant oil spray to fruit trees this month as long as buds have not started to open.
Some vegetable and flower seeds can be put directly in the garden this month if the soil is dry enough to cultivate. Before using a tiller, form a ball of soil in your hand and drop it about three feet from the ground. The soil is ready to till if the ball crumbles into small pieces.
Postpone planting if the ground is soggy or snow is lurking in shaded areas. If the weather is fine, the following dates can serve as a guide. Sow leaf lettuce, onion seed, and spinach any time after the first of the month. Seeds of larkspur, poppy, alyssum, calendula, snapdragon, and stock also tolerate the early March garden environment. Plants of the cabbage family that were started in the house can be set out beginning the 15th. Head lettuce, peas, radishes, and turnips are also candidates for sowing on or after the 15th.
Plant potatoes after the 20th. The 20th is a good time to start warm weather crops in the house that need about 2 months to grow before being set out. These include garden favorites like eggplant, peppers, and tomatoes. Beets and chard are suitable for sowing directly in the garden during the last week of March.