Thursday, October 20, 2016

Fall Planting Tips

Fall is the best time of year to plant most trees and shrubs. Usually temperatures are cool, but not too cold for root growth, and rainfall is plentiful: the perfect conditions for new roots to form and plants to become established. In addition, many garden centers get in a fresh batch of plants, so you might find that particular tree or shrub that was sold out when you looked for it in the spring.

 It is important to give roots a good place to spread out, so when you plant, dig your hole wide but not too deep. Wide is usually defined as 2 or 3 times the size of the container your plant came in. Just as important, don't dig the hole too deep. You want the plant to rest in the hole slightly above the level that it was growing in the container. If you over-estimate how deep the hole should be and have to back fill, remember that the loosened soil underneath the plant will settle, lowering the plant in the hole. You may want to compensate for the settling by planting a bit higher. The depth of the hole is important because Memphis soil generally contains a lot of clay, and clay soil equals poor drainage. 

After you've dug your hole there is a big temptation (at least, this is true for me) to add soil conditioner, compost, or other amendments to encourage those roots to reach out into the soil and help the plant off to a good start. Plant scientists have learned that this is the opposite of what actually happens. Adding organic matter creates a difference in the texture of the soil in the hole and the surrounding native soil. This difference causes problems with water movement, as well as encourages roots to grow in a circular pattern in the amended soil rather than spreading out into the native soil. Just think about what roots do when they bump against an obstacle like the edge of a flower pot (or hard clay soil) : they take the path of least resistance and just circle around in that soft, amended soil you provided. So you want to create a more hospitable environment by loosening the native soil in a wide area, but resist the urge to add amendments.

Also, it is a good idea to check the root ball after you remove the plant from the container. If the plant has been growing in the container for a while, the roots may be crowded together in the pot. In this case, you may want to tease the roots apart with your hands to encourage them to spread out in the planting hole. If the plant has been in the container for a long time, the roots may be pressed together in a thick mass. In this case, you'll need to be ruthless about spreading the roots. You may even need to use a knife to score through the root ball. Cutting circling roots encourages the plants to send out new roots, and these new roots will have a better chance of growing into the native soil.

Roots that grow in a circular pattern around the plant, sometimes referred to as "girdling roots" can, over the course of years, actually strangle and kill an otherwise healthy plant. Sometimes this condition results from improper planting, and sometimes we inherit the problem from the garden center where we bought our plant. Case in point, consider the picture below. I came across this small tree last week, one in a group of newly-planted trees. My guess is that they were planted this past spring, as most of the trees still had the nursery tag on them. Notice the root encircling the trunk. This will prove to be disastrous over time.

What to do about this condition? At a minimum, the encircling root should be clipped so that it can't continue to encircle the tree. But this root makes wonder what condition the rest of the root ball is in. Since this is a small tree and appears to be planted fairly recently, I would dig it up and inspect the root ball. I'm guessing other problems may exist and could be corrected now. If no corrections are needed, little or no damage will be done by digging it up and replanting it, as long as it is well-watered through the fall.

Speaking of watering, this fall's strange, hot and dry weather conditions mean that you need to be extra vigilant about watering. Newly planted trees and shrubs have a small root system so they need regular, frequent waterings. This fall, mother nature has not been helping us out much with watering.

Click here for a short University of Tennessee Extension fact sheet on planting.

Wednesday, October 12, 2016

Camellia Fruit

Our fall-blooming camellia (Camellia sasanqua 'Winter's Joy') is loaded with buds this year, and I am eagerly awaiting the first sign of color. Last year, the first buds began to open in mid-to-late October. I always hope for an early bloom (or a late frost) so that I can enjoy the blooms before they get hit by a killing freeze.

While I was watering this camellia today (will this drought EVER end?), I noticed something I have not seen in the past: fruit. I had never heard of camellia bearing fruit (you experienced camellia growers out there probably have), so I looked it up on the internet. Sure enough, they sometimes do. Here's what the fruit (seed pods) look like.

This particular seed pod has already begun to ripen and has taken on a red color. Most others on this bush are still green. Apparently, if allowed to mature, these seed pods will burst open, exposing the seeds inside. 

Now, you are probably wondering whether these seed pods produce viable seeds. According to my research, the answer is yes, but since this camellia is a hybrid, the characteristics of the offspring are not predictable. Chances are, its offspring would not be as desirable as the parent plant. So I wondered if I should pick off these fruits so that the plant's energy would be redirected to the plant rather than these unwanted fruit. Some sites I found suggested that I should, but there are not a lot of these seed pods (a dozen or maybe a few more), and I wonder whether the plant would reap much benefit from my removing them. Besides, I'm curious to see how they develop. So I think I will leave these on the plant.

While researching the seed pods, I came across several sites that said some people like to remove some of the developing flower buds to increase the size of the remaining flowers. It seems that the plant must use a lot of energy to support many buds and if some those buds are removed, all that energy is directed to the remaining flowers. This makes sense and I've heard of people doing this with other flowers, for example, roses.
But these buds will be opening very soon so I wonder if it is too late for this strategy. It may be that the remaining bud would not have time to benefit from the additional energy available from removing the competing buds. Besides, I think I might enjoy having many small flowers more than a fewer number of large ones.

On the other hand, this camellia certainly has a lot of buds and it may be that simply removing a few would allow the others more physical room to spread out more. The scientist in me is curious. I think I will select a few bud clusters to experiment with, like the cluster on the left side of this picture. I'll chose a bud cluster like this one and remove all but one of the buds. Then I'll choose a second similarly-sized cluster of buds to use as the "control." It will be interesting to see if removing the competing buds results in any appreciable difference in the size of the bloom. Of course, I'll never know what would have happened if I had removed the competing buds when they first formed. Maybe that's an experiment for next year.

Saturday, October 1, 2016

Colocasia gigantea 'Thailand Giant'

Last year I bought a large species of elephant ear (Colocasia gigantea 'Thailand Giant' ) at my favorite local nursery and when fall came, I lifted the bulb for winter storage. Thai Giant is an enormous variety of elephant ear that is rated for zone 8b so chances are prettty good that the bulb will freeze in our area if left in the ground. Last winter it lived in our garage.

This spring I decided to plant it in a large pot for the summer. It did very well in the pot (although I probably didn't fertilize it as much as it needed), and it bloomed several times over the summer. 

Here is a closer look of the interior of the plant. You can see the three old bloom stalks with pod-like structures that must contain the seeds.

Several weeks ago, I discovered a tiny elephant ear coming up in the iris bed,and it appears to be an offspring of the Thai Giant. I've read that this type of elephant ear can be propagated by seed and that it is self-pollinating but I didn't know it would re-seed by itself. 

Now I'm wondering whether I can grow some more from these seed pods, but I've got a feeling this may be one of those lucky happenstances that I could not accomplish by plan. I might give it a try anyway. This is the only elephant ear I've ever grown that has propagated by seed.

Click here for an article on how to grow elephant ears from seed.