By Thom Morgan, Springmoor landscape manager
In last month’s blog, I mentioned that Springmoor experienced a lot of rain in June and July. August continued to be wet, and we got a break from the summer heat. I also mentioned that lawns, landscape plants and vegetables only need 1.5 inches of rain a week in summer, and just one inch of rain a week during the cooler months.
When you get too much rain, the ground becomes saturated and plants that can’t tolerate too much water die. If you have a spot that stays constantly wet, there are trees and shrubs that can tolerate high moisture, and low oxygen in the soil.
- Bald Cypress (Taxodium distichum) actually grows in water, loses its needles in the fall, and sends up roots, or knees, in order to gain access to oxygen.
- Dawn redwood (Metasequoia glyptostroboides) is another deciduous needle leaf that tolerates high moisture levels, and the needles turn a greenish pink in the fall before they drop.
- Red maples (Acer rubrum) are found in floodplains in most of North America, make great street trees, and come in varieties bred for their brilliant fall color. Ask for Octobery Glory (red to orange) Red Sunset (Orange to red Fall color) and Autumn Blaze (yellow and orange).
- River Birch (Betula Nigra) are also found in floodplains and tolerate highly moist soils, but care should be taken when placing them in your landscape (their roots will seek out any plumbing you may have underground, and should not be located near any foundations, or sidewalks).
- Sweetbay Magnolia (Magnolia virginiana) is a small native tree which can be found in the low-lying areas of coastal North Carolina. It is deciduous, but does have nice white flowers in May. The Sweetbay Magnolia’s open growth habit is best suited to informal, natural gardens.
Some shrubs that tolerate high moisture are:
- Anise (Illicium parviflorum) is an evergreen which grows 10 to 12 feet tall, and makes a good informal screen.
- Winterberry Holly (Ilex verticillata) grows 10 feet tall, and about six feet wide. It does lose its leaves in the fall, but the female plants retain bright red berries through the winter. You have to play cupid with this plant, and be sure to buy a male cultivar (Jim Dandy or Southern Gentleman) to plant nearby the female plants.
September Gardening To-Do List:
It’s still not too late to plant fall and winter vegetables, but the window is closing fast as daylight hours shorten and temperatures drop.
Sow red top clover, or annual rye grass if you choose not to have a winter garden. These plants fix nitrogen in the soil, and you plow under it in the spring. If you already have planted your fall and winter vegetables, be sure to fertilize with 8/8/8, or 10/10/10 fertilizer once a month. Plants still need to be fed. Also, watch out for those white cabbage butterflies. You can apply Sevin dust, but this gets washed off any time it rains. I keep hearing about products with Bacillus Thuringiensis, or BT, but can never find it here in the Triangle. This sounds like the way to go, as the BT bacteria prey on cabbage worms. If anyone knows where to buy BT in the Raleigh area, please let me know.
Bird netting works very well, and prevents the butterflies from laying eggs on broccoli, cabbage, and collards. The netting can be removed once the frost kills the butterflies.
If you have a cool season fescue lawn, now is the time to aerate, and re-seed. Seed at a rate of one to two pounds per 1,000 square feet—too much seed will choke itself out.
Plan ahead for October, and make room for fall annuals such as pansies, snap dragons, kale and ornamental cabbage. At Springmoor we have the following plants in bloom:
- Kaleidoscope abelia (Abelia grandiflora kaleidoscope) has hundreds of pink blooms, plus evergreen green, yellow and white leaves that turn pink and red in the winter—a true year-round interest plant.
- Butterfly bush (Buddleia davidii) come in white, pink, red, and a purple so dark it appears black.
- The Encore azaleas are living up to their name as they bloom for the second time in a year. Find them at your local nursery under names like Autumn Cheer, Autumn Embers and Autumn Monarch. They cost about three times as much as regular azaleas, but the payback is a plant that blooms twice—sometimes three times—a year.
- Finally—crape myrtles and rose of Sharon (mentioned in last month’s Floral Focal Points blog) remain in their heyday in September.