Cold weather and wet soil usually stop gardeners from digging in the ground during the month of March. However, there are many other activities that satisfy the urges to start planting and other tasks that will result in a more beautiful yard once warm weather arrives. Timing and proper techniques are important for many late winter and early spring jobs.
Week 1 Plan your vegetable and flower gardens. Seed catalogs, U of M Extension Website: extension.umn.edu or the Andersen Horticultural Library at the Landscape Arboretum are great places for information.
Week 2. Purchase a shamrock (oxalis) plant at your local florist or garden center to provide a living, green, St. Patrick’s Day decoration.
Week 3 Cut some branches from forsythia, flowering plums or other spring blooming plants and place in containers of warm water. Soon flowers will pop open and brighten your home before spring arrives.
Week 4 Move pot-bound houseplants into bigger pots. Use new potting soil and water well. Fertilize all interior plants with a soluble fertilizer mixed at ½ strength.
Week 5 Clean-up and sharpen garden tools and inventory supplies you will need for the upcoming growing season.
Pick a nice day and go outside and turn the compost pile. This will give you some exercise and get the compost “cooking” again.
March is the best month to prune flowering crabapples, oaks, mountain ash, honeylocust and other trees and shrubs that are susceptible to diseases if pruned during warm weather. Remove broken, rubbing and crowded branches, and double leaders, and always make a clean cut just past the swollen branch collar. No tree wound dressing is needed.
Fruit trees and grape vines should also be pruned this month. Apples and other fruit will be larger and have better flavor if the trees have been pruned so each branch has good exposure to sunlight and are well spaced up and down and around a central trunk. Grapes will overproduce and have small berries unless the vines are pruned every year.
Older flowering shrubs that have grown too tall and are not blooming well can be rejuvenated by using “chain saw pruning,” This involves cutting the whole plant down to within 3”-4” of the ground. It is amazing how fast shrubs will grow back following this severe pruning and they will have much better form and flowers in coming years.
What to Plant
1. Sow onion seeds indoors and provide good light for the seedlings as they emerge. Onions grown from seed and planted outdoors in May will produce the best bulbs and they will store better than ones started from onion sets.
2. Annual flowers including ageratum, impatiens, dwarf marigold and petunias may also be started indoors in March. Use a sterile seed starting mix, supplemental light and bottom heat for best results. Keep the lights close to the young seedlings and transplant to larger containers as the plants grow.
3. Plant dahlia, tuberous begonia and caladium bulbs in pots or flats using a soil mix containing slow release fertilizer. You will have good size plants that are perfect for use in mixed containers, hanging baskets or flower gardens in May.