What to Do in the Garden in June (Cool-Climate US)

Start and sow

• Direct-seed summer vegetables from the last week of May through the end of June (UMN Extension).
• Continue succession plantings of carrots, beans, and sweet corn for staggered harvests (Purdue Extension).
• Start seeds of cabbage, Brussels sprouts, broccoli, and cauliflower for fall-garden transplants.
• Finish planting annuals; the best window runs through the end of June.

Prune and maintain

• Prune spring-flowering shrubs after their blooms fade, and remove faded flowers and seed pods on lilacs.
• Deadhead flowers June through September (UMN Extension).
• Mulch to control weeds and conserve moisture once soil has warmed; supply about 1 to 1.5 inches of water per week to lawn and garden (Purdue Extension).
• Water newly planted trees and shrubs deeply every 7 to 10 days when rain is lacking.
• Mow regularly but mow high; divide perennials through the third week of June (UMN Extension).
• Remove tomato suckers while they are 1 to 1.5 inches long, and pinch mums and annuals for bushier growth.

Harvest

• Harvest spring plantings of broccoli, cabbage, and peas; pull cool-season crops before they bolt and turn bitter.
• Stop harvesting asparagus and rhubarb around mid-June so foliage can rebuild the crowns (Purdue Extension).
• Pick strawberries and protect ripening fruit from birds with netting.
• Let spring-bulb foliage yellow and wither before removing it.

Sources

Reviewed 2026-07-18. We cite university Extension, government, and established horticultural sources — and never invent pesticide rates or dangerous treatments.

• University of Minnesota Extension — Upper Midwest home garden care schedule — Direct seed summer vegetables last week of May through end of June; deadhead June-September; divide perennials through 3rd week of June; mulch/annuals windows through end of June
• Purdue University Extension — June garden calendar (Indiana Yard and Garden) — Stop asparagus/rhubarb harvest around mid-June; succession plant carrots/beans/sweet corn; start fall brassica seed; prune spring bloomers after flowering; 1-1.5 inches water per week; harvest spring broccoli, cabbage, peas, strawberries

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