Green Thumb – Summer Checklist

Posted: July 13, 2018

By the middle of summer, some of our enthusiasm for gardening may be waning a little bit. However, some of our very favorite plants are about to appear in our gardens to be enjoyed this month.

Annual plants should be filled out and looking beautiful in July. Annuals in the ground will benefit from some summer attention. Deadheading and fertilizing will encourage new growth. Always wet the soil before fertilizing. Annual plants in hanging baskets and containers may require daily watering in hot or windy conditions.

Let’s take a look at what is going on with our perennials in July.

The queen of the July perennials has to be the daylily. With over 20,000 registered varieties, there should be something for everyone to like. They have been waiting patiently all spring and early summer. Now it is their time to shine. Here are a few tips to help your daylilies thrive and keep them at their peak performance. Daylilies need a sunny location, frequent watering and an application of 5-10-5 fertilizer before bloom. Pinch off flowers as they fade and remove entire stalk as soon as flowering is finished to conserve energy.

If you have already been pinching back mums, asters and sedums for fall color, stop pinching them back late this month so that they will have time to develop for the fall.

Delphinium, salvia, catmint and decorative geraniums may be cut back to their base following the first flowering. This will promote a second, late summer bloom period.

In your shade garden, hostas should be sporting their showy flower stalks.

Roses should be fertilized with a 20-20-20 liquid fertilizer for a final time late in July. Do not fertilize roses after August first. Monitor roses for blackspot and remove infected leaves.

Lawn care is fairly simple during the summer months.

Mow grass at a high level of 2 1/2- 3 inches in the heat of summer. Grass clippings can be left on the lawn but raking to avoid clumping is recommended. Avoid the use of herbicides in the hot weather. Do not fertilize lawns until the fall.

Let’s check in on the fruit trees and the vegetable garden.

Crabapple, apple, apricot, peach and plum trees should have all ground level sucker growth pruned out below the soil level.

We all love our tomatoes and worry when they are having problems. To keep our tomatoes healthy, it is very important to give them an even supply of moisture. Heavy watering and drought conditions are deadly for tomatoes. Keep it even. Mulching is a good idea. It is also helpful to prune off the leaves closest to the ground. Mulching and pruning will keep soil born diseases from splashing up on your tomatoes during watering.

Broccoli, beans, spinach, cool-season lettuce and cabbage seeds can be sown toward the end of July for fall harvest.

Consider planting an herb crop next year. Swallowtail butterflies love dill. This is a great project for all of the family.

And finally, a few activities for our shrubs and trees.

Overgrown shrubs like red twig dogwood, lilac and forsythia can still be renovated in July by pruning out one-third of the old canes.

Watersprouts are small branches that grow vertically on trees. If you see them on any of your ornamental flowering trees, fruit trees or redbud trees, prune them out as they will take energy away from the tree.

Barb Lindholm – University of Illinois Extension, DeKalb County Master Gardener


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