Extending Summer Color into Fall
About the time those of us who live on the coast are emerging from our morning-evening fog cycle and finally getting some reliably warm weather, our summer-blooming flowers are beginning to look tired. Now that we can actually enjoy more time in our gardens and even some dinners outside, it adds to our pleasure to have our flowers looking bright and colorful. To achieve this we need to deadhead the spent flowers and maybe add some plants that come into bloom in late summer.
When a plant finishes blooming it wants to go to seed, but if the finished blooms are cut off so the plant can’t reseed, the plant will put out new blooms in an attempt to complete the cycle. This is the purpose of deadheading—to prolong the bloom period by removing the spent flowers. How you do this is dictated by the plant and how it grows. The age of the plant can also affect how it needs to be cut back. On young perennial flowers you may want to just remove the flower stalks by cutting back to a lateral branch where you can see a new bud or new leaf growth. For some plants this is not enough, or it is too laborious, and it’s preferable to cut the stems right off down to the basal foliage near the ground.
In my Inverness garden I have a lot of lavenders and sages along with penstemon, catmint and yarrow. These are the ones I go to work on to get another round of flowers. I start by looking at the plant to see where I see signs of new growth. On the yarrow, I can see new foliage near the ground. If I cut back the old stems and flowers to this point I’ll get some new flowers and a fresher looking plant. The second blooms will never be as strong as the first flowering, but the refreshed foliage is much nicer to look at and produces some new blooms. Sometimes the plants themselves almost beg you to cut off the old stems. Shasta daisies and some of my sages and lavenders open up in the center after flowering making it easy to see just where you should cut to allow the new center foliage to replace the old growth. By contrast, the penstemon stalks stay tall. On plants like these you can get good repeat blooms by cutting down to a lateral branch that is putting out new leaves and perhaps new buds. With the large catmint plants, I may cut off individual spent flower stems at first, but after the majority of the flowers are brown, I shear off the top half of the whole plant. I lose some of the emerging buds this way, but the stem-by-stem work is too laborious. Large lavender plants can be dealt with in the same way. Many summer annuals (especially leggy petunias, lobelia and alyssum) also respond to a good haircut.
The rest of the color in my late summer garden comes from perennials I’ve chosen for their later bloom time and some annuals like zinnias that I use to fill in empty spots. Reliable late bloomers are Mexican sage, Russian sage, echinacea, caryopteris and many types of asters and sedums. Dahlias are wonderful workhorse plants that just keep blooming right on into fall. The nurseries will be full of chrysanthemums that are bred to bloom in fall colors and provide a good transition into fall, especially as a color accent near ornamental grasses. We may also continue to get good color from our roses or hydrangeas that are attractive even after their flowers fade. So with a little labor and some thoughtful plant choices, we can have color for our “summer” even though the calendar says September.