May is perhaps one of our most enjoyable gardening months, and June is when we really start to enjoy the rewards of spring-planted vegetables. One of the biggest assets of gardening during this time is that the soil is warm, which creates perfect growing conditions for many of our favorite plants. It’s not too late to plant almost anything in the garden, so continue planting summer-flowering annuals and perennials, as well as summer vegetables.
This is the time of year that your oriental and Asiatic lilies are growing or are about to come into bloom. The lilies are so beautiful, but sometimes the flower cluster outweighs the stem to stand upright. I like to stake these plants before they come into bloom, if possible. Thin bamboo stakes work well for this. Simply slide them as close to the stem as possible and tie them firmly, but not tight, at several spots below the blooms so as not to distract from the sensational flowers. I leave these stakes up until the stalks die and then remove them at the same time I cut down the stalks.
May and June are also the perfect months to plant dahlias for fall bloom. Remember that these are tuberous roots and should be planted as such. For best results, good fertile soil and a sunny location are important. After I dig a deep hole that is about one-and-a-half times the width of the tuber, I add rich organic soil or compost mixed with the native soil. Then I add ¼ cup of a low-nitrogen fertilizer (like 5-5-10) and mix this well in the planting spot. Once this is done, I plant the tubers in the hole about a foot deep. Be sure not to cover the tuber with the soil more than an inch until the growth on the tubers is visible. Over a period of the next few weeks, I slowly add soil until the tuber reaches the original soil line.
Roses are another favorite in my summer garden and can be planted now with no problems. Many rose varieties tend to be high-maintenance, so I like to look for roses that will not involve as much work but will still bloom all summer and into fall. I have had a lot of luck with the flower carpet roses. With only water and fertilizer, they will continue to bloom until the fall nights get below 50 degrees. I do suggest two things that really help with the flower production of these bushes. Before the roses begin to flower, treat them with Bayer All-In-One Rose and Flower Care. Then, after every flowering, remove the spent blossoms and lightly fertilize the plants.
I look forward to seeing three trees bloom this time of the year: dove tree, loblolly bay, and southern catalpa. These trees are not common landscape trees and may be more difficult to find, but they are worth tracking down as they offer sensational white flowers that bloom in very different ways.
Dove trees and loblolly bays (more often called by the genus Gordonia) are small trees that showcase their flowers in late spring until it gets hot in our area. They like good soil, I also make sure to plant them where they get some late afternoon shade. The flowers of dove trees look like tiny white handkerchiefs waving in the breeze. The tree is a member of the blackgum family, so it is okay to plant in damp locations. The same is true of loblolly bay, as its native habitat is swampy pinelands. To me, its flowers resemble a single anemone.
One of the best large trees you see in bloom around Birmingham this time of the year is the southern catalpa. It was one of the earliest street trees planted here but fell out of favor as new trees became available. If you see this large tree covered with its clusters of white blooms in early May, rest assured it is a showstopper. If you need a large tree in your home landscape, this one would be beautiful. In fact, the great thing about all of these trees is that once established, they are curiosities for your garden.
Floyd’s To-do List: May/June
Continue planting flowering annuals and perennials. Lantana, Angelonia, marigold, and all of the salvias do better when planted once the soil has warmed up rather than in early spring. The keys to successful summer flowers are water and fertilization. Be sure to water before your plants look like they are beginning to wilt. Liquid feeding every other week throughout the hot days of late June and July is recommended. After that, monthly fertilization should be sufficient.
Remove all of the suckers at the base of crepe myrtles, as well as any awkward shoots that seem out of place in the plants. Cut the suckers as close as possible to the central trunk. If they are tender enough to pull off, that is an even better way to remove them.
Mulch now if you haven’t already done so. My favorite mulch is pine straw. It makes no difference whether it is longleaf pine that usually comes in the round bales or the regular straw that comes in square bales. Remember that the main purpose of mulch is to help protect plants from dry conditions, so place it as thick as possible around plants without covering them up. I like to water the mulch to stabilize it, especially if it’s windy. An added benefit of mulch is that it helps the landscape look more manicured.
Prune and shape azaleas that have finished blooming. Remove tall shoots, crossed branches, and spent blooms that are still present. Then reduce the size of the plants if needed. Using a hand pruner is best. Once the pruning is complete, fertilize with a formulation like 15-0-15 to promote new growth and good plant color.
Support the Gardens
Now is a great time to support the Birmingham Botanical Gardens by becoming a Friend of the Gardens. Membership dollars benefit the ongoing stewardship and enhancement of the Gardens, as well as educational programs and outreach activities. As a member, you’ll receive benefits such as access to members-only classes and events, free general admission to Antiques at the Gardens, and discounts on certain workshops, as well as many other perks. Visit bbbgardens.org to learn more and sign up to become a member.
John Floyd has been gardening in the Birmingham area for more than 30 years. In addition to his day-to-day experience, John has degrees in horticulture from Auburn and Clemson Universities and was editor-in-chief of Southern Living. For daily tips and more garden information, visit birminghamgardeningtoday.com.