Cold injury on Loquat trees
A viewer reported last summer one of the loquat trees started wilting and then several trunks died while other parts of it lived. There is bark damage on the dead limbs, but the living trunk has put out blossoms. We consulted Texas AgriLife Extension fruit specialist Jim Kamas. Here’s what he says. It’s almost undoubtedly cold injury. Loquat is a relatively cold hardy sub-tropical, but in some years when warm temperatures happen during the end of January it can cause a loss of hardiness in all plants and with a cold front and a sudden drop in temperatures, this can cause freeze injury on almost everything. It is not surprising that loquats were injured even if they were in a protected location. The trunk injury and the description of how the plants collapsed, along with trunk weeping, are consistent with how we see plants respond. Here’s what to do: Keep the plants well-watered, but not saturated, over the winter. The drought last winter greatly exacerbated the problem with cold injury. Trees can indeed repair themselves, but don’t be surprised if limbs continue to collapse and bark sloughs off of the trunk. Just keep the plants in as good of health as possible, remove dead wood, and hope for the best.
When to fertilize our shrubs, trees and perennials?
After extreme heat, your landscape definitely needs a little help before the summer arrives. Although fertilization is not necessary for every plant, every year, I would suggest fertilizing to give your plants a nutrient boost during the spring growing season to help prepare them for the stress of summer. With plant nutrients, a little bit goes a long way and more is definitely not better. If you give your plants too much fertilizer, they’ll put on a lot of new growth and may look great in the spring, but then when summer arrives, they won’t have enough water to support all that new growth and they’ll be even more stressed. With perennials and flower beds, consider using a layer of compost as your initial mulch. Compost will provide a very small amount of nutrients, which is likely all your perennials will need. For trees and shrubs, use an actual fertilizer product and choose one that is slow-release, meaning that the nutrients will be released slowly over time. No matter which type of fertilizer you choose, be sure to follow the label directions and don’t over-apply. Also be sure to water your trees, shrubs, and all your plants very well this spring. All the care that you give them now will help tremendously during the heat of summer, when you really won’t be able to provide your plants as much water as they truly need. And as for your lawn, you should wait until full green-up, most likely late-April or early May, to fertilize.
When to prune ornamental grasses like bamboo muhly, inland sea oats, and fountain grass?
Now is the perfect time for this task. Like many temperate zone plants, most ornamental grasses go dormant in the winter, and reemerge in the spring and the best time to prune them is sometime during dormancy. If your ornamental grasses go dormant early and you can’t stand the look of the messy brown leaves, prune them as early as late fall or early winter. But if your ornamental grasses have attractive seed heads or some other nice quality while they’re dormant, you can leave them alone until as late as the end of February. Here in Central Texas, we warm up pretty early, and you’ll want to get any pruning done before new growth begins to emerge. The smaller the plant the easier it will be to prune, and you’ll need to cut straight across, leaving most grasses at a height no more than 6 inches from the ground. If the plant is small, it won’t be too hard to do this with a pair of pruning shears while holding the grass with one hand. But as the plant gets larger, you may need to use a larger pruning tool, such as a pair of hedge trimmers, or even an electric trimmer, which will allow you to us both hands to cut in a flat plane, parallel to the ground. If the grass is very large and thick, you may want to tie the leaves into one or several small bundles, using masking tape or garden twine, to keep it in place while you prune.
Why is it recommended in Central Texas to prune roses in February?
We must have recently had an influx of new gardeners from more northern climes, since I’ve been getting this question a lot lately. As you will soon find out, if you don’t know already, Central Texas has two seasons: summer and NOT summer. Spring, which most people associate with gardening, is virtually non-existent, so plants go from dormant to wide-awake in what seems like a matter of minutes. That is, if plants even go fully dormant at all. Many roses, especially if planted in a warm, protected spot, may not even drop all of their leaves in winter. So how do we decide when to prune? Well, we have to be familiar with our general weather patterns, and shoot for the tiny window between non-growth and growth. With most roses, this isn’t too difficult, since you can almost watch the buds swelling, just beneath the surface of the stems. Most years, it’s a pretty safe bet that bud-swelling is going to happen sometime before the end of February, so that’s why we prune this month. With roses, it’s very important to choose buds that will grow outward, rather than toward the interior of the plant, in order to improve air circulation in the center. This helps to keep these often disease-prone shrubs from getting black spot and other fungal and bacterial problems, and so it keeps you from having to spray them. As you’ve noticed, rose leaves usually have a lot of red in them, so frost and wind damage, which expose the red pigments, and even just normal leaf-drop in the winter, are often confused as disease issues. “Normal” color patterns in leaves will be very symmetrical and usually first appear as a red mottling near the margins. Diseased leaves will appear splotchy and the pattern will normally not be symmetrical. And one more note on pruning: there are a couple of exceptions to our February pruning advice. Vining roses should not be pruned until after they’ve flowered. And shrub roses, such as Knockout, may be pruned virtually anytime, to keep them in shape.
Mexican feather grass, Nassella tenuissima
If you’re looking for billowy texture, this is definitely the plant for you. No other ornamental grass is quite as delicate and feathery. Mexican feather grass performs best in well-drained soil, near other low-water use plants in the garden. Give it regular water during establishment, then water only sparingly, during the driest of times. The deep green foliage of feather grass contrasts nicely with the soft blonde seed stalks produced in the summer. Like other ornamental grasses, you should prune feather grass each year during dormancy, mid-winter is a good time, before the new foliage emerges in the spring. Each plant will get about two feet tall and a foot wide, but these great planted in masses, that will sway and swoon in a nice summer breeze. They are prolific reseeders, and will most likely escape to other areas of your garden. You may find this quality endearing, especially if you have some empty spaces you want to fill in. But if you find this annoying, simply pull the seedlings up when they’re small.
Maroon bluebonnet, Lupinus texensis ‘Texas Maroon’ a Texas Super Star
Although you may never see them, maroon bluebonnets actually ARE found in nature, along with a spectrum from white, to pink, to deep blue. The reason we see so many blue bluebonnets, is because of genetics. The blue flower color is dominant and the other colors are recessive. Like our other native wildflowers, maroon bluebonnet seeds should be planted in the fall. But now is the perfect time to plant transplants. And be forewarned: since bluebonnets are annuals, with the parent plant dying after seed-production, the maroon color will be lost in your population if there are any blue bluebonnets in the area to pollinate them. Bluebonnets perform best in full sun and prefer well-drained soil. The crown of this plant remains at soil level, with only the leaves and flower-stalks elongating, so if the soil is too heavy or stays too wet, your bluebonnets will rot quite quickly. If you’d like, you can allow the seeds to naturalize in your garden, or you can collect them once the pods have dried on the plant. Bluebonnet seeds have a very hard seed-coat and require some physical scarring to soften and imbibe water. In nature, scarification occurs in varying ways, but if you collect seed for resowing, you could use a file to slough away some of the seed coat before planting.
Mexican orchid tree, Bauhinia Mexicana
A great choice for attracting butterflies and hummingbirds to your garden. Mexican orchid tree is rather small for a tree, getting only 4 to 8 feet tall and spreading to as much as 6 feet wide. With this growth habit, Mexican orchid TREE is really more of a SHRUB, and it looks beautiful when allowed to grow like a shrub, with fuller foliage and more flowers, so be sure to give it plenty of space to spread out. This plant can be a little frost-tender, so place it in a protected spot near your home, in a southern exposure perhaps, where the walls of your house might radiate a few extra degrees of warmth during the winter. But even though Mexican orchid tree likes to be a little warmer when it’s cold out, it doesn’t easily tolerate the intense heat of our full summer sun, so choose a spot that’s protected from the harsh afternoon rays, or one that gets bright, filtered light all day. And if you’re a real butterfly fan, be sure to plant this tree close to a window or porch, where you can sit and enjoy the fluttering all summer long. Bauhinia is covered with large and showy, but at the same time very delicate, pink or white flowers, from summer through early fall. Mexican orchid tree is normally deciduous, but may freeze to the ground in harsh winters. If it does freeze, simply cut back the dead trunks when you begin to notice new growth in the spring, probably be sometime in March. And an important quality for many of us, Mexican orchid tree is listed to be deer resistant.
Grandma’s Yellow Rose, Rosa ‘Nacogdoches’, a Texas Superstar plant
This very vigorous shrub has vibrant yellow, almost tulip-shaped, Floribunda-type blooms and very deep green foliage. It’s also very thorny, so be careful not to place it too close to paths or doorways. It has a very upright and bushy habit, getting up to 5 feet tall and over 3 feet wide. Grandma’s Yellow begins blooming in early spring and will be covered in flowers all summer long. As all Texas Superstars are, it is disease-tolerant and insect-resistant, a very important quality for a rose. And another important quality for many people who enjoy roses, the flowers are fragrant, with a light spicy note. They also do very well as cut flowers, remaining beautiful in a vase for many days. In order to perform well in the landscape, Grandma’s Yellow needs at least 6 hours of full, bright sun a day, and it prefers well-drained soil, with a little organic matter. But it will also tolerate clay soils, as long as it is not over-watered and has good drainage. It does need a little more water than our xeric recommendations, and although it doesn’t require it, Grandma’s Yellow will be more vigorous and have more flowers if it’s fertilized in the spring and a few times during the growing season. Grandma’s Yellow looks great planted as hedges, so try it instead of red-tip Photinias, Eleagnus and Ligustrum.