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Gardening Tips

Container Gardening

Now is the time to start your summer planters. Even if your spring flowering plants like pansies still look good, it is time to rip them out and start over. Pansies are pansies, and they will soon fade with the first hot days of summer.

Containers look great in any garden, but are especially useful in a small garden, or as an accent to a doorway or patio.

Bigger is usually better when it comes to containers. Small pots simply dry out too fast and the plants often look stressed. Big terra cotta pots are wonderful, and now many better grades of fiberglass resin pots look great and are easy to handle. Sometimes you even have to touch the pot to determine if it is plastic or the real thing.

Holes in the bottom of the pot are essential to provide good drainage. Without drainage the roots will drown and the plants will languish and die. It is also important to use a good quality potting soil for good root aeration and drainage. Remember roots need oxygen to respire just like us.

When choosing plants for containers, the possibilities are endless. There are the tried and true geraniums, New Guinea impatiens and petunias. Angelonia is a wonderful plant for adding color and height to a container. Be sure to also add plants that will spill over the side, such as ivies, lamium, and verbena. And don’t forget foliage - silver-leaved dusty millers and plants such as coleus add textural interest and will look terrific all summer. Ferns provide an elegant look for shady spots. Finally, experiment with perennials and grasses, they can look really great in the right container.

Grow Glorious Roses

Roses are coming back. After years of people getting frustrated with growing roses in this climate, roses are once again hot because of the new disease resistant varieties.

Our favorite this year are the Knock Out® roses – Pink Knock Out® which was co-discovered at the Morris Arboretum, blooms continuously from June to October, and is fully hardy in the Delaware Valley. It is an absolutely carefree landscape rose shrub rose, reaching about 4 feet tall by wide, with remarkably disease resistant foliage.

You can also choose from Knock Out® rose (Rosa ‘Radrazz’), Double Knock Out® (Rosa ‘Radtko’), which has cherry red double flowers, and Blushing Knock Out® (Rosa ‘Radyod’), with shell pink blooms. All of the plants in the series are on display in the Morris Arboretum’s rose garden, where we have mixed them with perennials and annuals to add longer seasonal interest versus traditional rose beds.

As the blooms fade, cut back to a leaf with five leaflets to encourage new growth and new blossoms. Stop fertilizing by mid-August.

Water roses deeply once or twice a week, in the morning when at all possible. Watering at night leaves the foliage wet and leads to fungal disease problems. Soaker hoses are also a good idea.

Great Summer Perennials

Some top perennials for heat tolerance and summer color include:

Daylilies
Daylilies provide great diversity in color and a long blooming season. Plants are available in reds, orange, yellow, and new hybrids in cream and lavenders. Each variety typically blooms for two to three weeks. With an assortment of varieties, you can have daylilies blooming from early June through August.
For a dramatic effect, plant them in mass or in a mixed border with other perennials and shrubs.

These perennials will last forever. For best results, divide them every two to three years waiting until after they flower in late summer to divide. Cut back the foliage to about 6”. Lift with a spading fork and pull apart into three or four pieces. Replant them 12-18 “ apart.

Sedum Autumn Joy
Sedum is a succulent, which are plants that are very tolerant of hot dry conditions. It has handsome blue gray foliage and interesting texture. The most common varieties have flowers in the pink family that bloom in late August followed by deep rose colored seed heads. Use them to make dried arrangements in the late autumn and winter.

Echinacea – Coneflower
Most common varieties feature purple or deep rose flowers with an orange center. Different cultivars have different heights. Their long flowering season starts in June and continues through August. Cutting back dead flowers encourages reblooming, however leaving the seed heads on attract birds.

Plant in mass for a dramatic effect. Large groups make a nice mid or back border plant.

The root of the Echinacea is the source of the medicinal herb that boosts the immune system.

Now that summer is here don’t forget to mulch and deep water (good soaking twice a week) any new plants you installed in the spring.