June Ornamental Garden Tasks and Tips

  • By Pat Chadwick
  • /
  • June 2015 - Vol. 1 No. 6

June is one of the busiest and most rewarding months for the ornamental gardener. It’s busy because there’s so much to accomplish before the really hot weather descends upon us. It’s rewarding because, at the end of the day, you can take pride in the landscape you have created. Just don’t become overwhelmed by all the work that needs to be done to create that perfect landscape. After all, gardening is not a competitive sport – or is it?

Garden centers are bursting this month with lots of ornamental plants to choose from.   As you select bedding plants (annuals) or perennials for your garden, don’t be dazzled by all the colorful blooms. While it’s nice to see the color of the blossoms, it’s more important to buy good quality plants. Look for plants that are well proportioned with sturdy stems and healthy, disease-free, pest-free foliage. If possible, carefully slip the plant out of the pot and check the roots to make sure they are well developed but not root-bound. Healthy roots should be white. If the plant has brown or black roots, that’s a bad sign. Just put the plant down and quietly step away.

With so many plants to choose from, it’s easy to become overwhelmed. Before buying anything, think about the plant’s requirements for sunlight, water, and soil. If you have a shady yard, for example, don’t buy a plant that needs full sun. If you don’t have a lot of water to spare for gardening, then don’t buy a water “hog.” If your soil is alkaline, don’t buy an acid-loving plant. If you have a deer problem, think twice about buying hostas, daylilies, or other plants that Bambi might find tasty.

The nursery trade is flooded with new varieties of annuals and perennials every year. Be daring and try something new. Just avoid buying one of this and one of that. Otherwise, your garden may take on a jumbled look. For example, annuals that are used to cover a large space in the garden look much more appealing to the eye if you plant just one color in a big swath. Tip: If you chose wax begonias as bedding plants, the bronze-leaved varieties tend to do well in full sun whereas the green-leaved varieties can tolerate some shade.

Consider planting a few herbs in the ornamental garden to add interesting color accents. For example, purple-leaved basil, such as ‘Purple Ruffles,’ harmonizes well with yellow, pink, or lavender-blue flowering plants. ‘Pesto Perpetuo,’ which is a green-and-white variegated form of basil, is another good choice for adding texture and visual interest. Chives are particularly charming in the ornamental garden with their airy globes of lavender blossoms. Gently mounding golden oregano and golden marjoram as well as creeping thyme also add color and interest and serve as useful ground covers. Use your imagination and try incorporating other herbs that appeal to you.

As annuals become established, deadhead spent flowers to encourage the plant to produce another round of flowers. Yes, pinching or snipping off dead blossoms probably sounds tedious. However, a few minutes spent deadheading each week will keep those annuals blooming well into the growing season.

Except for Irises, which can be divided later in the summer, divide spring and early summer flowering perennials after the blooms fade. Instead of cutting the clump into two or more pieces with a knife or sharp-edged shovel, try gradually prying the roots apart with two spading forks placed back to back. This technique takes more time and effort but damages fewer roots than cutting the clump apart.

Leave foliage from daffodils and other spring blooming bulbs in place until it turns brown and begins to dry. Do not braid or tie the foliage. It needs to continue photosynthesizing in order to provide nutrients for next year’s blossoms. If you set out bedding plants to cover the bare spots left by the bulbs, be careful when you are digging in the soil to avoid damaging the bulbs.

For containerized plants, keep close tabs on their water requirements. This is particularly critical if you’re planning to go away on vacation. Group containerized plants together near a hose or other water source so that it will be easier for your neighbor or other helpful person to water your plants for you in your absence. Place the plants where they will be out of the afternoon sun. This will help them conserve water. Don’t forget to check all hanging baskets daily, particularly those that are in full sun, and water as needed.

Water trees and shrubs deeply and infrequently to help them get through the summer heat. This is particularly important during the first few growing seasons after a tree or shrub is planted. It’s also important for all plantings during drought conditions.

Stake taller plants, such as foxglove, yarrow, and delphiniums to prevent them from flopping over. This is particularly critical if your garden is in a windy site. Likewise, some asters, chrysanthemums, and other mounding plants that tend to flop over may require support.

If you want to propagate new plants from woody shrubs, trees or perennials, now is the time to take stem cuttings. To learn about propagation techniques, see Virginia Cooperative Extension Publication No. 426-002, “Propagating by Cuttings, Layering and Division,” http://www.pubs.ext.vt.edu/426/426-002/426-002_pdf.pdf.

Inspect rose bushes for insect damage from aphids, mites or thrips. Aphids may be eliminated simply by directing a strong water spray from the hose on the rose bush. If Ladybugs are present in the environment, they may eliminate aphids without any intervention on your part. Otherwise, spray the shrubs with insecticidal soap to kill the insects. Be sure to follow the instructions on the container before applying.

Protect bees and other beneficial insects from harm because we depend on them to pollinate our ornamental plants and food crops. If it’s absolutely necessary to use a pesticide, spray in the evening after bees have returned to their hives.

As the weather grows warmer, mosquitos make their appearance on the scene. Contrary to what some people believe, mosquitos cannot breed successfully in moving water. They can, however, breed in a puddle of standing water, such as that found in your birdbath or in a saucer under a potted plant or in a drain pipe, especially if the water remains in place for more than a week. With that in mind, monitor all potential mosquito breeding places and remove standing water immediately.

Don’t get excited if your bleeding heart (Dicentra spectabilis) foliage turns yellow and starts to die back. This is normal behavior for this plant, which generally goes dormant by mid-summer. Just cut the yellowed foliage back to the ground. If this leaves a large gap in your landscape, fill in the space around the roots with some annuals or later blooming perennials or perhaps some ferns or hostas. Everblooming varieties do not go dormant.

Now that you’ve planted, weeded, and watered your garden and patrolled the area for pests and diseases, you deserve a treat. Bring a few blossoms indoors to admire. The best time to cut flowers for bouquets is early in the morning or late in the day when temperatures are coolest. Cut the stems at an angle (for better water uptake) and place them in water immediately. If you can’t bear to cut those beautiful posies, consider cutting just a few and then filling out your bouquet with interesting or colorful foliage from perennials such as ferns and hostas or branches from shrubs, such as abelia and spirea.