April Gardening Calendar

The following gardening calendar was created with help from two of our favorite gardening reference books:  Month by Month Gardening in Wisconsin: What to Do Each Month to Have a Beautiful Garden All Year by Melinda Myers and The Wisconsin Garden Guide – The Complete Guide to Vegetables, Flowers, Herbs, Fruit, & Nuts, Lawn & Landscaping, Indoor Gardening by Jerry Minnich.

EARLY APRIL

·         Start vegetable, herb and annual seeds indoors.

·         Thoroughly rake your lawn to reduce the risk of snow mold. 

·         Mow your lawn if the grass is two inches or longer. 

·         Remove mulch from perennial beds so the soil can begin to warm.  Work the soil once it has dried out.  

·         Test gardening soil in several places to use as a fertilizing guide this season.

·         Plant fruit, balled and burlapped, and container-grown trees.

·         Remove any protective coverings or wraps from existing trees.

·         Plant shrubs applying a two to three inch mulch layer to conserve moisture and minimize weeds.

·         Uncover strawberry plants.

·         Set out viola and pansy plants in containers on the porch or plant in the ground when it can be worked.

·         Keep roses covered until the weather is consistently above freezing.  You can vent coverings on warm days and cover back up during frost advisories. 

·         If you wish to transplant roses, do so now before new growth begins. 

·         Add a two to three inch layer of fresh mulch around existing trees and shrubs. 

·        Thoroughly water any trees and shrubs that may have been exposed to deicing salt.

·        Continue to remove and destroy Eastern tent caterpillar egg masses on flowering plums and cherries.

·         Finish removing and destroying any green and black knots from twigs and branches of ornamental plums, almonds and cherries.

·        Eliminate European pine sawflies on mugo pines by removing infested branches.

·        Reduce the spread of spruce gall by pruning out the small swollen sections that look like miniature cones on the stem while they are green and the insects are nesting inside.

·        Plant asparagus roots and fertilize young asparagus plantings (one to three years old).

·         Plant cool season crops such as carrots, chard, kohlrabi, leaf lettuce, mustard greens, onions, peas, spinach and potatoes. 

·         Fertilize ornamental shrubs and fruit-bearing bushes such as blueberries, raspberries, and grapes.   

·         Start fast-growing annuals indoors.

·         Repair damaged areas in your lawn by removing dead turf, loosening the soil, re-seeding and mulching. 

·         Divide hostas as soon as their leaves appear.  Water them thoroughly once they are transplanted.   

·         Prune spruce trees, arborvitae, and yews before growth begins.

·         Prune pines by removing one-half to two-thirds of the expanding buds (candles) in spring before growth begins.

LATE APRIL

·         Plant cole crop vegetables such as broccoli, cabbage, cauliflower and collards and cold tolerant annuals such as pansies, dusty miller, violas, and snapdragons.  Make sure to cover plantings during unexpected drops in temperature.

·         Apply Stein Crabgrass Control plus Lawn Food® to your lawn.

·         Plant hardened off spring blooming perennials and Wisconsin native wildflowers.

·         Transplant summer and fall blooming perennials.

·        Avoid pruning trees while buds open and leaves begin to grow.  It is okay to prune them once the leaves are fully expanded.  Note:  Do not prune oak trees once growth begins; prune only when dormant.

·         If Iris borer is a problem apply an insecticide once the foliage reaches six inches tall.  (It is not effective if applied later than this).  

·         Plant strawberry plants and lilies.

·         Uncover, prune and fertilize roses.  Use pruning paint to seal fresh pruning cuts if cane borers are a concern. 

·         Remove and destroy webbed nests from Eastern tent caterpillars on crabapple, birch and other ornamental trees. 

·         Friday, April 27th is Arbor Day.  Celebrate by planting a tree! 

Sources:

Minnich, Jerry. The Wisconsin Garden Guide – The Complete Guide to Vegetables, Flowers, Herbs, Fruit, & Nuts, Lawn & Landscaping, Indoor Gardening. 3rd ed. Madison: Prairie Oak, 1995. Print.

Myers, Melinda. Month by Month Gardening in Wisconsin: What to Do Each Month to Have a Beautiful Garden All Year. Franklin: Cool Springs, 2006. Print.