Contributors: Kathy Zuzek and David C. Zlesak, University of Minnesota Extension Educators
June is an amazing month in Minnesota- perhaps the most enjoyable one of all with generally nice weather and the fast rate of growth of plants in our gardens. It is definitely a month when there is a lot to enjoy in our gardens. Early season vegetables are ready for harvest and our ornamental plants are growing strong. In the midst of everything going on, please don’t forget to take time to relax and “smell the roses”.
Danger of frost and very cool night time temperatures are finally over for most parts of Minnesota. This means we can put out our warm season vegetables and flowers that are sensitive to chilling injury. This includes: tomatoes, peppers, cucumbers, squash, melons, cannas, coleus, and impatiens. Perhaps we have put some of these crops out earlier and protected them from frost. It is amazing how just cool night time temperatures in the high 30’s and low 40’s F can stunt growth of warm season crops. Warm season plants put out in our gardens now can outgrow those that may be suffering from chilling injury from our excitement to get them in early even if we protected them from frost.
Photo 1: 'Pink Promise' is a 2009 All-America Rose Selections winner with a wonderful fragrance. David Zlesak
Consider staggered, succession plantings of garden vegetables like bush beans and loose leaf lettuce to have a continual supply. Consider planting more each week or every other week. Some loose leaf lettuce varieties have been selected to have greater heat resistance and less propensity to bolting than others and are better choices during our warmer summer months. Succession planting is a great idea as well for some flowers with a short flowering period such as gladiolus. Plant gladiolus corms at two week intervals up through the middle of July in order to enjoy blooms over an extended period of time.
Photo 2: It is finally safe to plant warm season crops in most of Minnesota like this butternut squash. David Zlesak
Now is a great time to prune many of the recently spectacular spring flowering shrubs, if needed. Light to moderate pruning can be done to shape them, rejuvenate them, or simply to overall reduce their size. Such shrubs include forsythia, early blooming spireas, flowering almond, and earlier flowering lilacs.
June is a very active month of growth for plants. For most plants an ample supply of water typically means 0.75 to 1.0 inch of water per week. If rainfall is not sufficient, try to supply the remainder through irrigation. Consistent, deep waterings are especially important for new or recently planted trees and shrubs, newly planted seeds and transplants, and very sandy soils that do not retain moisture well.
Photo 3: Spring flowering shrubs like flowering almonds are finished blooming and now would be a good time to do some light to moderate pruning on them. David Zlesak