By: Lisa Briggs | 5/21/2020
Late May is usually a gardener’s favorite time of year! Every yards looks a bit like Munchkinland in technicolor. This spring’s weather has certainly delayed almost everything. So we find ourselves looking forward to a stellar June.
Let’s talk for a moment about Boxwood. Lots of established plants took a hit again this winter. If your Boxwood are yellowish, they are not infected with Boxwood Blight, they are suffering from winter damage. Give them until Father’s Day to do any pruning as buds for this season’s growth may have survived even though the foliage did not. Boxwood Blight is another matter, and since it was found in Dane County last year, the Garden Center will not be stocking Boxwood this year. For more information on determining the difference, follow this link.
It’s shaping up to be a wet spring, so watch for fungal development as soon as temperatures begin to rise. All of this moisture is sure to bring on cases of Powdery Mildew, Leaf Spots and Apple Scab. While fungus can be fairly easy to control on ornamental plants, treating fruit crops is trickier as you can’t use the systemic products. These types of fungicides and insecticides enter the tissue of the plant, making them unsuitable for eating. And this isn’t restricted to you and your family. Birds and small wildlife can be harmed if they ingest systemically treated fruits. There are great biological fungicides on the market. Both Serenade and Revitalize can act preventively.
Watch out for Cherry Leaf Spot and Brown Rot on any stone fruit crops such as cherries, plums and peaches. These fungal diseases can be prevented with a recommended fungicide. It is too late to treat for Peach Leaf Curl, but if you see it, make a note to remind yourself to apply a dormant spray of Lime Sulfur early next spring. And thinning the crop will lessen the stress on the plant.
It’s finally warm enough to plant out all those heat-loving veggies like tomatoes, peppers and eggplant. They’ll soon be growing like crazy, but may need to be monitored for a few pests. We’ve haven’t heard any reports of Cabbageworm yet, but are certain they are looming on the horizon. They’re pale green caterpillars and will devour any of the Brassicas. Pick them off or treat with Eight. And the Zimmerman Sawflies are active on Mugo Pines in the area. You can zap them with Sevin.
We’ll finish with a few words about all of the late emerging plants. We’ve seen a lot of “dead” Roses, Hydrangeas and Weigelas coming into the Plant Desk. Even though the top-growth looks really horrid, mature plants have established root systems. There is every chance that the plant will send new shoots form the roots. So be patient. If you have warranty questions, bring in photos. And do what you can to keep your affected trees and shrubs healthy and vigorous. Watering them if it gets hot and dry later this summer will go a long way.