University of Vermont Extension 
Department of Plant and Soil Science

Summer News Article


CLEANING ANNUALS AND OTHER JULY GARDENING TIPS
 
 
Charlie Nardozzi, Horticulturist and
Leonard Perry, UVM Extension Horticulturist
 
 
Cleaning summer annual flowers, protecting plants from birds, and watching for pests are some of the gardening activities for this month.

Continue planting vegetables such as radishes, carrots, and lettuce so that you'll have a continual supply of these vegetables into the fall. Seeds will germinate quickly in the warm soils, but so will the weeds. Be diligent about weeding, watering, and thinning your new seedlings.

Although summer annuals such as petunias used to benefit from a mid-season pruning in the past, most newer cultivars (cultivated varieties) either keep a compact habit or spread nicely as desired.   Some are self-cleaning, meaning their flowers fall off without needing you to prune them off or “deadhead.”  If flowers on these or other annuals such as marigolds and zinnias remain, deadheading them after bloom will keep the plants attractive, more bushy, and help them to bloom better.

If you're going on vacation and are concerned about your container plants, here are some tips for keeping them healthy. Water containers thoroughly before leaving and move them into a shady location where they won't dry out as fast. Place smaller containers in basins with a few inches of water that will slowly be absorbed by the plants while you're gone.  If gone for a longer period, line up a plant sitter but make sure you go over with them all the details you want done.  Grouping potted plants makes it easier for your sitter to not miss any.
 
Protect cherry trees and blueberry bushes from hungry birds. As these fruits ripen, the birds will be attracted to them. Place bird netting over the trees and bushes, propping it up with poles or stakes so the netting doesn't lay on the plants.  Make sure it is fastened to the ground, otherwise birds may get underneath and not be able to get out.  Otherwise, check plants daily for any birds that have slipped under the net.

Check tomato plants for large, green-striped horned caterpillars. A few can cause lots of damage, so hand pick and destroy them when found. Spray the organic pesticide B.t. (Bacillus thuringiensis) to control large infestations.

Protect your squash vines from the squash vine borer.  These clear-winged moths lay their eggs on the stems and the hatching larvae bore into the vines, causing the plant to wilt and possibly die.  Apply the organic pesticide B.t. every 3 or 4 days during July and early August to kill hatching larvae before they enter the stems.  A thin layer of wood ashes or moth flakes scattered around plants may discourage egg laying.

If these don’t work on the squash vine borer, slit the vine stem where it is wilting and follow back until you find the feeding grub.  Remove and destroy it, then bury the end of the vine so it hopefully will root and resume growth.

Summer is a great time to visit perennial nurseries to see what is in bloom, and add to your collection.  As virtually all the plants are in pots, it is fine to plant them now, just add some compost at planting, mulch, and keep them well-watered.  There are many local specialists you can find online under Vermont Perennial Display gardens  (pss.uvm.edu/ppp/vpdgli.html).     

(Charlie Nardozzi is a nationally known horticulturist, author, gardening consultant, and garden coach (CharlieNardozzi.com).     

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