It is interesting how gardening changes from year to year. For example, some years you can tell when spring is over when the lilacs are at the end of their bloom. Not this year. In our area the lilacs bloomed very early and then we had a killing frost that not only ended the bloom, but also damaged early fruit blossoms.
Although some gardeners continue to pick rhubarb well into the summer, harvest should end the first part of July. This is especially true if the patch is a fairly new one. Be sure to continue to cut off stalks that have gone to seed. Rhubarb plants require a lot of organic matter and large amounts of balanced complete fertilizer. Top dress with well-rotted manure or mulch in the fall. Continue to keep the patch weed free and if you need to move or rejuvenate the patch wait until next spring.
Asparagus is another spring crop where the harvest should be winding down the first part of July. It should not be harvested hard until the fourth or fifth year of growth and if the ferns are very small, they shouldn’t be harvested at all. Leave the ferns to grow so they can rejuvenate the roots going into the long cold winter. Cut the ferns after they have frozen and dried in late fall or leave them over winter to help collect snow for next spring. Whenever you cut the ferns, remove and destroy in case there are insects or disease in the stalks.
There is still lots of work to do in the asparagus patch. Keep the weeds out of the patch, even though this gets more difficult as the patch ages. Also, don’t let the patch dry out as stress always invites insects and disease. You need to keep looking for the asparagus beetle. This orange colored insect likes to eat the ferns especially the small ones. It can defoliate the ferns and can kill the plant if the problem is severe. This beetle lays black eggs on the tips of the spears. This distorts the spears into the shape of a shepherds crook, making the spear unacceptable for harvest. If you are into spraying, be sure to buy an insecticide that says it controls the asparagus beetle. I use a product called Eight by Bonide which seems to be fairly effective. After harvest, add nitrogen fertilizer that will help fern development. The bushier the asparagus, the better the yield next year.
Governor Mark Dayton has proclaimed July 19 as University of Minnesota Extension Master Gardener Volunteer Day in Minnesota! The program began here 35 years ago and currently there are more than 2200 active Master Gardeners in nearly all Minnesota counties who volunteer over 130,000 hours annually.