Last spring, I bought an eye-popping blue perennial salvia that turned out to be a great attraction for bees and wasps. It’s apparently very happy because it has almost taken over the border. I want to be sure I have this in my garden again next year. Should I simply cut it back, or try to move the whole thing to another part of the yard? And is this the time of year to do it?
UF’s Gardening Calendar (edis.ifas.ufl.edu/ep451#SECTION_9) says that we in Northeast Florida should divide and replant our perennials and bulbs in September. But as a friend once told me, plants don’t keep calendars, only gardeners do.
Whether it’s a herbaceous salvia (one that dies down to the ground each year but whose roots remain alive and send up new growth the next year) or a woody evergreen (pretty much what it sounds like, with stems covered with bark) the process of transplanting is the same.
First, dig the new hole for the plant. You’ll want to move your salvia quickly from its location to its new “digs.” You have already seen the plant’s light requirements (full sun) and clearly want to repeat that As with most plants, you want the new location to provide good drainage.
The tricky part for Northeast Florida gardeners is to find a day that is not too hot. This September, the days may be getting shorter, but the temperatures still feel like summer. It will be hard to keep the roots, disturbed by transplanting, moist and able to re-establish in our hot days.
Dig out as much of the root ball as you can and plant it so the root crown is slightly above the soil line. Water it in well and be sure it doesn’t dry out while getting established.
Since your plant is very large, you might want to divide it. You certainly can, but keep in mind that dividing is a bit trickier than simply moving the whole plant. Also consider that if your salvia is evergreen it will be fussier than its herbaceous cousin.
When the plant is out of the ground, tip prune any excessively long roots to make the root ball relatively even. Remove some of the foliage at its base and find where there are logical sections or clumps to divide. A sharp or serrated knife works well for this job. Again, work quickly to prevent further damage to or drying of the roots.
Most perennials benefit from division every two to three years. Division maintains the plant’s health and vigor, as well as filling your and your friends beds and borders with beautiful additions costing only a little sweat equity.
Last spring, I added some great-looking red canna lilies to the front full-sun border to complement the oranges and yellows out there. Now, I’m seeing speckled yellow spots on the leaves. Is this just because the plants are through for the year, or is it a disease?
Cannas are tropical rhizomes that provide stunning blossoms of pink, yellow, orange and red. But many of us are just as attracted by the cannas’ unusual leaves. Depending on the cultivar, the large paddle-shaped leaves can vary from shades of green or bronze to striped/variegated and add interest and contrast even without the flower stalks. Again, depending on the cultivar, they grow from one and a half to eight feet tall, so there’s probably one to fit your space, no matter how big or small. Even people with no yards can enjoy them as container plants.
That is, so long as you can provide 6-8 hours of sun and moist, organic, well-draining soil. These plants do well during our hot summers. Like most plants (and people) in Florida, they enjoy a little shade during the middle of the day. They even grow in shade, though that will inhibit their blooming.
While in flower, don’t allow the soil to dry out. When the flowers end for the season, you can cut back on watering. If you are that paragon of gardeners who is diligent about dead-heading your garden plants, you can prolong the flowering season by removing spent blossoms. But, for lazier gardeners, that’s not necessary for the plant’s health.
Cannas are greedy feeders and will appreciate a general purpose fertilizer (5-10-5 or 10-10-10) monthly, or a few applications of controlled-release fertilizer.
For all its positives attributes, gardeners need to scout their cannas for evidence of damage by many insect pests and any number of fungal, bacterial and viral diseases. Among these diseases is canna rust.
If it’s rainy and hot in the South, expect rust. Long periods of humid weather, poor air circulation and waterlogged soil promote the appearance of this fungal menace. Yellow to tan pustules develop on the foliage, sometimes spreading to the stem. if you wipe a finger over a leaf with these pustules, your finger will come away with a rusty brown stain. Hence, the name.
When the pustules mature, they release large amounts of spores. The leaves become dry and fall off prematurely.
The first step is to remove and discard all infected plant parts and plants. Take it to the curb and not in the compost bin. The home compost pile doesn’t get hot enough to kill the pathogen. It will just come back to haunt you. As you prune, sterilize your shears between cuts so you don’t spread the disease.
Then, improve air circulation. That may mean transplanting some of your display to increase the spacing between plants.
Going forward, don’t use overhead watering if at all possible. The droplets of water that remain on the leaves will provide the perfect environment for the fungal spores blown by the wind, thus beginning the disease cycle all over again.
Next year, before the hot, rainy, humid weather arrives, consider applying a commercial fungicide. There are several effective products available, usually a copper or sulfur-based preparation. Be sure to select one that lists fungal rust as a disease for which the product is designed and that the product is safe for cannas. Then, apply according to the label’s instructions.
Catalogs and plant tags will assure you that cannas are low-maintenance plants. My experience is that, indeed, that’s true. But low maintenance is not the same as no maintenance. With a modicum of attention, today’s canna cultivars become true jewels in the summer garden, and well worth effort.
Paula Weatherby is a Master Gardener Volunteer with the Duval County Extension Service and the University of Florida/IFAS. For gardening questions, call the Duval County Extension Office at (904) 255-7450 from 9 a.m. to noon and 12:30 to 3:30 p.m. Monday through Friday and ask for a Master Gardener Volunteer.
This article originally appeared on Florida Times-Union: Garden Q&A: September is perfect for transplanting salvia