Daylily rust can be treated

By Audrey Post
MS. GROW-IT-ALL

Q: I have dwarf reblooming daylilies with numerous buds on all but two plants. Those two have a yellow scale on the underside of numerous leaves that is visible on the top, too. Until now, these have been easy-care plants. I have them planted in full sun, and I water them with a drip hose from a well when it fails to rain for a week. What do you suggest?

A: What you’re seeing might be what’s called “daylily streak,” which is a minor leaf disease causing more yellowing than most gardeners find attractive. But from your description, I think the problem is daylily rust, which is more serious.

Daylily rust is a fungus that is spread by airborne spores. It was first discovered in the U.S. in 2000 here in Florida and in Georgia. Since then, it has spread to at least 30 other states. It starts out looking like a water spot, which spreads and forms small pustule in the center, which contains powdery spores that are spread by wind or movement of the plants. To the naked eye, the foliage has yellow streaks with rust-colored spots and smears.

Take a white facial tissue and rub it across the affected area. If a yellow-orange stain appears on the tissue, that’s a sign your plant has daylily rust -- Puccinia hemerocallidis.

The rust can be treated, but it is labor intensive. First you need to carefully remove infected foliage from the garden, remembering that movement of the plant spreads the spores. Put the foliage in a plastic bag, seal it and dispose of it in the trash. Don’t compost it or burn it.

Some gardeners advise removing all the foliage from that bed to contain the fungus. When the new foliage starts to grow, apply fungicide. The standard practice has been to apply two different fungicides on an alternating schedule.

The Florida Department of Agriculture and Consumer Services’ Division of Plant Industry recommends commercial growers use two of these four fungicides: propaconizole (sold under the trade name Banner Maxx); azoxystrobin (Heritage); flutolonil (Contrast); myclobutanil (Systhane). Be sure to follow all label directions and precautions.

That said, daylily rust won’t kill your plants; they just won’t perform as well or look as good as they otherwise would. It’s your choice how much effort you want to put into protecting daylilies from this disease.

One friend dug out her entire daylily bed and replaced the plants with daylily cultivars known to be resistant to rust. Reputable growers and local nurseries know which plants are resistant. Another friend simply removes the infected foliage when she sees it and accepts the fact that she has a little rust in her daylily bed.

Unfortunately, some of our most beloved cultivars, including Stella d’Oro, have been found to be susceptible to rust. Like rose gardeners, some daylily gardeners want a particular plant badly enough to do the work required to keep it healthy.

I suggest you remove the two infected plants and see how the others in that bed fare. You can always spray later if you think you need to. To minimize spore dispersal, place an open garbage bag over the plant and pull it out by the roots, then flip the bag right side up and tie it securely. Any spores should fall to the bottom of the trash bag.

Radio Show: Gardening with "found objects"

This week's show was about converting "found objects" into unusual planters and gardening containeres. The show was in conjunction with a demonstration on the same topic I gave at Tallahassee Nurseries a couple of weeks ago.

Reader suggestions for clearing new beds

By Audrey Post
MS. GROW-IT-ALL

Last week’s column dealt with clearing weeds from an area in order to create a flower bed, and I suggested removing the weeds by hand. Two readers wrote with additional, and very different, suggestions.

“The best way to prepare a new bed is to mulch it heavily with hay. That will kill the weeds. Do not till. Do not use poisons. Continue to add more hay as it decomposes into the soil,” e-mailed Steven P. Christman, senior scientist and editor at Floridata.com, a very informative and useful local gardening Web site. A Florida master gardener with a Ph.D. in biology from the University of Florida, he has used this method in both vegetable and flower gardens.

Christman’s advice brings to mind one of my father’s favorite gardening books, “Gardening Without Work” by Ruth Stout, who also believed in the no-till method using hay. In addition to smothering weeds and saving your back, it also continuously improves the soil structure.

Bob Brown wrote to suggest using calcium cyanamide. “I have used this compound many times, and it is completely safe if handled correctly (i.e., with gloves),” Brown said in his e-mail. “It really does kill everything growing, plus dormant seeds. It is inexpensive and not ecologically dangerous to water systems as it breaks down to nitrate, which is readily used by the succeeding plants as a fertilizer, and leaves no residue. In lower doses, it is used as a commercial nitrate fertilizer.”

A Web site he recommended, http://www.improve-your-garden-soil.com/, gave the following description:

“Calcium cyanamide is a granular material that at first breaks down into substances poisonous to seeds but later converts into valuable nitrogen and lime. It is a grim coffin-gray in color and even looks poisonous to handle, but is safe if used as directed. The soil to be treated should be plowed or rotary tilled and leveled just before application. After 60 days you can plant seed, but disturb the soil surface as little as possible to avoid bringing up new weed seeds. The 60-day wait is one drawback to this material. Since soil should be warm during treatment, this means you have an unplanted lawn or garden during the major part of the growing period, which some gardeners find too unpleasant a sight to face.”

“A lawn I treated in this way four years ago came up without a single weed and, except for a few seeds blown in from the outside, has had no weeds since.”

This Web site is the personal project of a lifelong gardener named Robert Harris, who seems committed to helping fellow gardeners learn about the importance of soil. Our growing season is a bit longer than 60 days, but other than that, the information seems applicable here.

Radio Show: Keeping critters out of the garden

Today, our show focused on how to keep critters, both wild and domestic, out of your garden and planting beds. You can download the show by clicking on the link in the right rail for one week after broadcast; after that, go to my Home Page and click on the radio show archive link. Feel free to add your suggestions in the comment section below.

Skip 'Weed & Feed,' pull weeds from future beds

By Audrey Post
MS. GROW-IT-ALL

Q: I have an area along a sidewalk path that I want to turn into a flower garden. Right now, it is covered in different weeds. Can I spray "Weed and Feed" on those weeds and remove them from the area after they die? After that, I want to add some manufactured soil mix and plant my flowers and cover them with pine straw. Will the "Weed & Feed" be impossible to remove from the soil and kill whatever I plant in that area?

A: Whether you’ll be able to remove the “Weed and Feed” from the soil is really a secondary issue to whether the product will remove the weeds, thus allowing you to plant flowers in the area. Most “Weed and Feed” products are intended to feed the predominant plant in a given area while killing or preventing the growth of other plants.

In the case of grassy areas, “Weed and Feed” blends for lawns fertilize turf grass while inhibiting the growth of weeds and/or killing those that are present. Read the label to make sure you’re using a blend that feeds your specific kind of grass.

“Weed and Feed” formulas for flower beds fertilize the plants that are actively growing in the bed while inhibiting seed germination, generally preventing the growth of new weeds but also stopping any flower seed from germinating. It requires removing the weeds that are already growing before applying to be effective.

Using any kind of “Weed and Feed” concoction without removing existing weeds will simply feed the weeds that are there and prevent any seeds in the soil – whatever they are – from germinating. Since you want to convert a weedy area into a flower garden, this is not the right product for the job.

The best way to remove the weeds from your future flower bed is to dig them out by hand. You can use a chemical weed remover – not a “Weed and Feed” but a weed killer -- but you’ll have to wait until the residue has washed out of the area before you plant. The label on the weed remover will tell you how long you need to wait after application before you plant, but it sometimes takes multiple applications to kill existing weeds – especially if there are a lot of them. This could take a while, so you’ll save time and money as well as going “greener” if you dig out the weeds.

Once you have the weeds out, you can amend the soil with peat moss or compost to improve its structure and quality. I’m not sure what you mean by “manufactured soil mix,” but it doesn’t sound like anything you want to put into the ground. Save it for containers.

Radio Show: What plants like

Today, frequent co-host Stan Rosenthal, Leon County forester, and Ms. Grow-It-All discussed a little basic botany: what trees and other plants like. Most problems with trees, shrubs and other plants can be traced to one of their basic needs.

Test soil before transplanting shrubs, trees

By Audrey Post
MS. GROW-IT-ALL

Q: I have some sasanquas that are about three feet tall that I would like to transplant. I have tried three times and each time the shrub died. I get as large a root ball as I can and water them regularly but so luck so far. Any suggestions?

A: It could be one of several things, or a combination of them. Do the sasanquas like the new location? Sasanquas, which are a type of camellia, need partial shade and slightly acidic soil. Too much or too little sunlight will cause your shrubs to decline, as will a soil that’s alkaline. Make sure the new location meets the plant’s needs.

Before you transplant your shrubs, invest in a soil test. You can pick up everything you need – instructions, soil sample bags and a small cardboard box for mailing – at your county extension office; in Leon County, the extension office is at 615 Paul Russell Road. The cost is minimal and it’s much cheaper than the price of a new sasanqua.

If possible, prepare the entire planting bed instead of an individual planting hole. Spade or till 8 to 12 inches deep and mix inpeat, compost or other organic matter. Based on the results of your soil test, add any fertilizer, micronutrients or acidifying materials that might be needed.

When you dig the planting hole, make it two to three times the diameter of the root ball and just deep enough for the plant to sit at the same depth it did before. Don’t work the soil any deeper because it could cause the root ball to settle, which would make it too deep.

You say you water them regularly but what would be sufficient water for an established plant isn’t enough for one that has just been moved. Make sure you build a collar of soil around the plant, out about as far as the drip-line, to form a basin. This will direct water to the roots instead of allowing it to run off. And unless we’ve had plenty of rain, water it at least every other day so that the soil is moist to a depth of 12-14 inches. This will encourage deep root growth, which helps shrubs survive drought. Cover with a layer of mulch that’s 2 to 3 inches deep.

It’s a little late in the season to transplant sasanquas, the ideal time being November through February to allow the root systems to become established before summer heat arrives. If you decide to move them now, keeping your shrubs well-watered will be critical.

Radio Show: Recovering from the deluge

Today our show was broadcast live from Tallahassee Nurseries, where Ms. Grow-It-All was leading a workshop later in the morning on "Gardening in Found Objects." Our radio show topic today was helping your plants recover from extended, heavy rainfall, such as the deluge North Florida experienced earlier this week. It appears that most of the region received at least 8 inches of rain over three days. Landscape architect and horticulturist Rob Apsley, ASLA, of Macon, Ga., was our special guest.

Fertilize apples, citrus lightly if late

By Audrey Post
MS. GROW-IT-ALL

Q: I have an apple tree (Golden Dorsett, as I remember) which had lots of apples last year. I read I should have fertilized in December but didn't. Now it has blooms. Should I wait until June or go ahead and fertilize it now? Another query: My orange tree, which is 8 to 10 years old, really got zapped this winter. It lost all but a few leaves but I think I see some little green buds coming out from the few green limbs that are left. Should I fertilize or withhold? I was afraid it couldn't take the shock of any fertilizer right now.

A: One of the great things about gardening in this region (Zones 8 and 9) is the ability to grow apples and other cool-climate fruit trees alongside citrus and other warm-climate fruit trees. The key is to get low-chill varieties of the former, such as Golden Dorsett and Anna apples, and cold-tolerant varieties of the latter. However, even citrus varieties considered “cold tolerant” were damaged in our colder-than-usual winter.

Your orange tree should have had its first fertilizer application of the year in February, with subsequent applications in May and August. Go ahead and fertilize it lightly now; it shouldn’t shock it if you don’t overdo it. Apply as normal in May and August.

As for your apple tree, there’s not a lot of existing research on fertilizer and apples in Florida, so I consulted Leon County Horticultural Extension Agent David Marshall. He said the standard application rate is one pound of a balanced fertilizer such as 10-10-10 for each year of tree age, up to 15 pounds total per year. That total is divided between two applications in January and June. He recommended taking half the June fertilizer amount and applying it now, then applying the other half in June.

“It's not an exact science, but generally apples will benefit from fertilization and from watering when it's dry,” he said. “Of course, the best starting place for any plant and fertilization is doing a soil test first to find out what's already available to the plant. It's worth investing $7 in a soil test before spending $20 on a bag of fertilizer.”

More on camellia pruning: Melanie Klein read last week’s column about the camellia planted so close to the house that the homeowner can’t get behind it to paint, and she wrote to offer the following suggestion:

“I was wondering if the person with the overgrown camellia might, instead of getting rid of it, consider tree-forming it. That might allow access for painting the house and create a striking accent.”

Tree-forming, or pruning the camellia into a tree shape instead of the usual rounded bush shape, could be an option, depending on the distance to the house and roof. It’s worth exploring, especially if the camellia has sentimental value.