Perennial Gardens in Late July

Perennial Gardens in Late July

Although perennials usually return year after year, these gardens need on-going maintenance in order to keep them looking their best from spring through fall. Late July is the perfect time for some flower garden tweaking. If you get out early in the morning to avoid the heat, and spend thirty minutes to an hour on the following tasks, you’ll be happier with the look of your perennial bed. Here are 6 tips for improving your perennial garden in late July.

1. Deadhead Daylily Plants

The early flowering daylilies such as Stella D’Oro and Happy Returns need a total deadheading right now, while the July blooming varieties can be cut as individual stems go by. Clip the old flower stems and browned leaves down to the base one by one, or use a hedge trimmer to chop the entire plant back to the ground. If you shear the entire plant back, it will create new foliage that looks good through autumn.

The daylily stem on the right can be cut down – the flower is finished, and the seed-pod on that same stem can be removed. This photos shows the difference between a daylily bud and a seed pod: the buds (one seen here on the left) are thin, while the seeds are round and fat. The slender buds start to take on the color of the flowers, while the round seed pods are green fading to tan.

2. Cut Unattractive Perennials To the Ground

Some early-flowering perennials are not an asset in the garden by the end of July. Spiderwort, penstemon, and some salvias, for example, are not improved by a simple deadheading. These can be cut right to the ground. Many will respond by growing new foliage that looks better, while others will remain dormant for the rest of the summer but return again next spring.

Spiderwort (Tradescantia virginiana) is one of the perennials that isn’t attractive once it finishes flowering. It can be cut right to the ground in late July.
If the foliage on your peony plants still looks green and attractive, this perennial can be deadheaded to neaten the plant up, but most of the stems and leaves left in place. If the leaves get mildew or have dried out and are no longer attractive, the entire plant can be cut back to ground level.
Catmint (Nepeta varieties) can be left as is, sheared in half to make a neat, round ball, or cut to the ground. If you trim this plant to the ground it will produce soft, fresh foliage in about two weeks.

3. Pull Weeds

The summer weeds explode at this time of year. Be on the lookout for crabgrass, purslane, carpet weed, spotted spurge and plantain, and pull or hoe them promptly. Since many of these can germinate in and under your perennials, look closely so that you can remove them before they get too large.

These are random weeds that have germinated quickly in July.
Watch out for poison ivy! Seeds for poison ivy are dropped by birds and blown into gardens, so this plant might pop up in and among perennials. It’s a good idea to wear garden gloves when you’re weeding so you’re protected should you grab a poison ivy seedling when you’re pulling other weeds.

4. Shear Lavender

Once your lavender flowers have faded to gray, shear this plant with hedge trimmers, cutting the finished flowers stems and about an inch of the foliage. This will help the plant to stay thick and full, and frequently stimulates the production of a few more flowers.

When the lavender flowers turn from purple to gray, it’s time to shear the plants to keep them full and thick.
Here is the plant after shearing. You can save some of your cut flower stems for potpourri.
When you shear the old stems off you also trim a half-inch to an inch of the foliage too, and this keeps the plant round and full. When sheared annually, these plants are less likely to splay open and show woody stems.

5. Add Some Annuals

Yes, we know you love perennial plants, but adding a few annuals at this time of the season will keep you smiling into October. In any bare or open areas, or next to perennials that you’ve recently cut down, just spread some time-release fertilizer such as Osmocote or Shake n’ Feed, and plant a few annuals in that area. Water them in well right after planting, and be sure to spray with a rabbit repellant such as Plantskydd immediately. You’ll be rewarded with annuals that develop quickly and flowers until hard frost.

These Profusion Zinnias have been planted near perennials that have finished flowering and are going dormant for the rest of the summer. The Zinnias will quickly double in size, and will flower for two or three more months.

6. Keep Up The Watering

Since it remains dry on Cape Cod, be sure to water your perennials deeply every 5 to 7 days. Note that irrigation systems that go off for 20 or 30 minutes at a time are not soaking your plants deeply.

July is a time to harvest vegetables, pick blueberries and flowers.

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  1. Pat McDonald on August 4, 2022 at 8:19 am

    Great tips and information. Than you

  2. Pat McDonald on August 4, 2022 at 8:22 am

    Thank you for the great tips for perennial maintenance and suggestions on adding annuals

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