Special thanks to Forrest W. Appleton and volunteers of the “Master Gardener Hotline” in support of the weekly gardening questions and answers.

Question:
Mr. Rodriguez, I have been told that I should water my new zoysia grass and my new landscaping plants right before there is a freeze as this will protect them from the freeze. Is this true?
Answer:
Landscape plants, including turf grass, that are suffering from drought stress will be more affected by freeze damage than those that have been properly watered. However, watering them just prior to a freeze will not help if they have not been properly watered in the weeks and days before that freeze.

Question:
David, I moved a woodpile this week and found some huge ugly bugs that look like giant grub worms. They are 2-4 inches long and about 1/2 -3/4 inches in diameter. I put them in a dish on the deck thinking that they would freeze that night, but it didn’t get cold enough. They stayed in the dish for two days and on the third morning they were gone. Occasionally, we have a possum that comes through the yard and I assume they became its supper. I also took photo, taken with a ruler so you can see how big they were.
Answer:
No photo is necessary. But thank you. These are the larvae of the Rhinoceros Beetle. They are beneficial and do no damage to your plants. They are normally found in compost piles or other sources of decaying organic material.

Question:
Mr. Rodriguez, what are the roles of hybrids in vegetable production?
Answer:
Hybrids are the offspring of two different species or their infraspecific units. These resulting crosses are normally done for the purpose of improving some aspect of the plant; larger fruit, more fruit, flavorful fruit, disease resistance, plant size (larger or smaller), or other desirable characteristics.

Question:
Mr. Rodriguez, when is best time to prune the lower limbs on a Mexican White Oak/Monterrey Oak?
Answer:
You should leave the lower limbs on the tree until they get to be at least one inch in diameter as the tree is using the leaves on these limbs to support its growth. They can be pruned at any time after that.

Question:
David am I able to cut back my Ruellia ‘Katie’ ground cover, and if so, how and when is the best time to do it?
Answer:
You can cut your Ruellia ‘Katie’ back as severely as you desire, even to the ground. I recommend that you wait until any danger for frost or freezing is past to do your pruning and then just cut out the freeze damaged parts. This will give you much earlier blossoms.

Question:
I have a bed of Pink Skullcap on my front yard. I was told to cut them back to the ground in the winter, even though they do not appear to be frozen. Is this correct, and if so, how do I cut them back?
Answer: Pink Skullcap, if left unpruned, will get leggy and ugly like many of the perennials. Right now (about mid February) cut it back (shear) by about half and it will put on new growth and remain full.

Question:
Mr. Rodriguez, can I put my caladium bulbs in the ground now and cover the soil with tarp. We really haven’t had a cold winter.
Answer:
I would not advise this. Caladiums need warm soil to initiate growth. Putting them in cold soil only invites their rotting. I would wait until mid March or early April to plant them; however this would be a good time to purchase them while the availability is at their best.

Question:
David, I have three maiden grass shrubs (ornamental grass). Would you please tell me when to prune the shrubs and how low (far from the ground) do I prune them.
Answer:
I assume that your Maiden grass is Miscanthus sinensis which is cold hardy here and not one of the other Miscanthus species which are not cold hardy. The grass should be frozen and brown by now. Just enjoy its presence in your landscape as it is. Then when the dangers of freezing temperatures are passed, cut it to the ground. It will re-sprout from its roots.

Question:
Mr. Rodriguez, what should I be doing for camellias in February? I know they need acid soil and I have amended my soil here in central Texas but, what else should I be doing in the winter.
Answer:
Camellias not only need acid soil, they also need a well drained soil. There is little extra that needs doing during January or February. Just check for insects such as scale, aphids, and spider mites. Use a dormant oil spray for control of any insects you find. You should fertilize your Camellias in early March to support their spring growth.

Question:
Dave, it is not difficult to find plenty of information on the benefits of using mulch in our landscapes. My concern is whether or not we can apply too much of a good thing. Are you aware of potential problems that could arise if extra thick layers (greater than four inches) of mulch are used at the base of ornamental shrubs and/or trees? I’d appreciate your opinion.
Answer:
The main problem with putting more than about four inches of mulch around trees and shrubs is that it encourages a shallow root system with roots growing into the mulch layer which is not good.

Question:
Mr. Rodriguez, I had my yard sodded with Bermuda Tif-419 last summer. What and when should I be doing to my yard in order to make my lawn look its best? I’m looking for tips on fertilizing, pre-emergent, height of mowing, weed control, etc…
Answer:
There is nothing that needs doing right now, unless there are a lot of winter weeds. If so, mow them to prevent them from going to seed. Pre-emergent herbicide for summer weeds should be applied about mid February through early March. All Bermuda and especially the hybrids such as 419 should be mowed low one inch to two inches and mowed frequently. Fertilizing should be done the first part of April.

Question:
David, why do some Spanish Oak trees keep brown leaves on all winter long instead of them dropping?
Answer:
Unfortunately I cannot give you a good answer other than it is in the genes of the individual trees. I can only guess that these trees are the result of some hybridizing that causes the leaves to continue into the winter and produce good fall color. And I can tell you that this is the way it will always be for those particular trees as they are not going to change.

Question:
Mr. Rodriguez, I’m looking for a drought tolerant, fast growing attractive, evergreen shrub to use as a privacy screen against my wrought iron fence. I’d like something that will grow to six feet or taller and is easy to care for.
Answer:
Choose from among Sandankwa Viburnum (Viburnum suspensum), Burford Holly (Ilex cornuta ‘Burfordii’), and Waxleaf Ligustrum (Ligustrum japonicum).

Question:
Dave, I received for Christmas a five-gal container of Purple Fountain Grass from a nursery. According to what I’ve read, I can plant it in January or February, but does this mean to wait for any cold snaps? What happens if it freezes afterwards? Also, can I divide the plant to make separate plantings in the landscape?
Answer:
I would recommend that you keep it in the container, protected from freezing temperatures until about March 1 and plant it then. Purple Fountain Grass is not real cold hardy and if you planted it now a freeze could kill it before it gets well established. I have had one in the ground that has survived for more than five years but we haven’t had a real cold weather during that period. You can cut the plant in two, three or four parts before you plant it. Just use a saw or large knife to cut the root ball.

Question:
Mr. Rodriguez, I have a Dracaena marginata plant in my office. The plant is doing well but the tips of the leaves are all turning brown. I make sure the plant is well watered. Any advice?
Answer:
The most common reason for tip burn in house plants is a build up of salts in the potting mix from the fertilizer that is applied. This is the reason that when watered, they should receive sufficient water to drain out the bottom into a saucer. This will flush out these salts. You should take your plant outside or to the shower or tub and let water run through it for several minutes.