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    Save the Date: Perennial Plant Society’s 30th Plant Sale is April 4, 2020, 9 a.m. – 1 p.m. at the new Expo 3 Building at The Fairgrounds Nashville. Here’s where you can find the newest varieties of perennials, shrubs, vines and annuals from local growers, along with long-time, never-fail favorites, ready for spring planting. Learn more at the PPS website.

     

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Special care for holiday cactus

Our Christmas Cactus usually blooms around Thanksgiving. Sometimes the buds drop off before they’re open. Can you tell me what’s wrong? What kind of care do they need?

Schlumbergera truncata

Thanksgiving cactus

It’s common to call all of those exotic looking winter-blooming houseplants Christmas cactus, but there is more than one type. (Schlumbergera bridgesii) is the botanical name for Christmas cactus, and it usually does flower around Christmas. But there is also S. truncata, or Thanksgiving cactus, which normally blooms about a month earlier.

In general, any of those “holiday” cacti need bright light and a moderate amount of water. Barbara Pleasant, in her book The Complete Houseplant Survival Manual, suggests letting the soil dry out a little between waterings, and providing a dose of a balanced fertilizer about once a month in winter.

Christmas cacti are photoperiodic plants – that is, they respond to the change in proportions of light and dark, and begin to form buds at the onset of longer nights and shorter days in fall. Blooms open a few weeks later.

They can also be finicky about a change in conditions once they begin to bud – if you move them around, for instance. “Once plants begin blooming, they may drop their blossoms if exposed to any kind of stress,” says Barbara Pleasant in her book about houseplants.

More information and care tips from the Clemson University Cooperative Extension Home & Garden Information Center: the Schlumbergera is native to Brazil, and they grow as epiphytes in tree branches in shady rain forests. They enjoy being outdoors in summer, but bring them indoors when nighttime temperatures get down to 40 to 50 degrees – and certainly before frost. Place them in a cool, dark room, and bring them out into bright light when buds begin to develop.

Here’s how to tell the difference between Thanksgiving and Christmas cactus: Look at the stem segments. Thanksgiving cactus each have 2 to 4 sharp serrations along the margins. The margins of Christmas cactus are more rounded. One other distinguishing factor: When the flowers open, look at the pollen-bearing anthers. The anthers of Thanksgiving cactus are yellow; those on Christmas cactus are purplish-brown, according to the plant experts.

 

Continue to care for new shrubs in winter

We planted aucubas and hollies in the spring and kept them watered all summer, and they’re doing well. Do we need to water them in winter, too?

Aucuba japonica

Replenish mulch at the base of spring-planted aucuba and other shrubs.

Spring-planted shrubs that received regular water should be well-established by fall, so you can cut back on the amount of water they receive. But don’t neglect them completely. It’s a good idea to replenish the mulch, adding enough so that it’s about three inches thick. Mulch holds moisture in the soil, and also keeps it from freezing and thawing as temperatures swing from cold to warmer and back again. Remove any dead or diseased leaves from under the shrubs before you add mulch, and remember not to pile mulch up against the trunk.

One other winter grooming tip: If you have deciduous trees in the area that have dropped leaves onto the shrubs, take time to remove the leaves, especially if there are so many that they would block the sun.

As I mentioned in last week’s question-and-answer, a yard-full of leaves is a good source of mulch for those shrubs. Chop them with the mower before you spread them on the ground under the shrubs.

Mulch garden beds with fall leaves

What’s the best way to use leaves as mulch in the garden? Can we just blow them off the lawn and into the garden beds?

leaves 2Most leaves can become a good source of mulch for garden beds. And yes, you could just blow them off the grass and into the beds, but it would be better to shred them before piling them onto your garden areas. Leaves that have been chopped up will decompose faster; a thick layer of leaves left intact may also smother the plants underneath, and prevent water from reaching the soil.

You can chop the leaves easily by mowing over and collecting them in a bagger attachment, or by using a shredder.

These guidelines for using leaves as mulch are from the UT/TSU Extension office:

*Use a 3- to 4-inch layer of shredded leaves around trees and shrubs in annual and perennial flower beds.

*Oak leaves may change the pH of the soil over time, making it more acidic, so you may have to apply lime to maintain a favorable number. If your beds are mulched primarily with oak leaves, you should have the soil tested about every three years. Oak leaves are also tougher and decompose more slowly, so it’s especially important to chop them before you use them to cover your perennial beds.

*Leaves can be mixed into kitchen garden beds and in beds where you plant annual flowers. Most of the leaves will decompose before planting time next spring. A bonus: if you have heavy clay soil, a thick layer of leaves tilled into the soil will improve the soil structure.

One other piece of advice comes from Deb Beazley, a naturalist at Warner Park Nature Center who leads workshops on organic gardening: When you rake leaves, set some aside for later. Next spring and summer, when you need more mulch, you’ll have a handy source of fall leaves to use.

“Cover them in bags so they don’t decompose by the time you need them next June,” she suggests.

Replace landscape plants in fall and winter

We have lost many of the shrubs around our home. How late can we replant all of the landscaping around our residence? Is November too late?

ball burlap treesIf you are planting shrubs and trees, November is actually a good time to replant. Trees and shrubs planted when they are dormant have an easier time establishing good root systems before they begin actively growing again next spring. They will need to be watered at planting time and throughout the season, but not as often as you would have to provide water in spring or summer.

Here are general guidelines from UT/TSU Extension for planting balled-and-burlapped and container-grown trees and shrubs:

-Choose your location and begin by digging a wide hole, two or three times the width, but no deeper than the height of the root ball.

-Handle the trees carefully before you plant. Never pick up or carry a tree by its trunk, especially a balled-and-burlapped tree, due to the weight of the root ball. If they can’t be planted right away, water the trees well and place them in an area away from direct sun.

-Water a plant in a container before you take it out of the pot. After you remove the plant, cut any roots that circle the ball of soil (if the roots and soil don’t come out easily, cut the plastic away from the root ball. Don’t pull the plant out by its trunk). Use a sharp knife to make two or three vertical cuts, and gently loosen the ball to expose more roots to the soil.

-Place the plant in the hole so that the top of the root ball is an inch or two above the soil line. Remove any nails or rope lacing and cut away the burlap, leaving the burlap at the bottom of the root ball. If there is a wire basket, cut as much of it away as you can without disturbing the root ball.

– Backfill the hole with the soil that was removed from the hole, watering when the hole is about half full and again after you finish backfilling. Rake over the soil to even it out with the ground, and cover the area with 2 or 3 inches of mulch (keeping the mulch away from the shrub’s trunk.

-Don’t forget to provide water to newly planted shrubs and trees if the weather is dry.