Purple heart is an amazing plant. Yes, it freezes to the ground for the winter, but it comes roaring out with new growth each spring.

Q: While visiting a friend I was admiring a groundcover bed she has. She called it “purpleheart,” and she said it’s a winter-hardy cousin to wandering Jew. How dependable is it? I’d like to plant some myself.

A: It’s an amazing plant. Yes, it freezes to the ground for the winter, but it comes roaring out with new growth each spring. It grows in sun or shade.

Purple heart is an amazing plant. Yes, it freezes to the ground for the winter, but it comes roaring out with new growth each spring.

I’ve seen several cities use it in thoroughfare medians. Those have to be some of the roughest, hottest growing conditions, yet it thrives. Go for it!

Q: I really thought I was going to lose my live oak due to the cold of February 2021. Several in our neighborhood developed cracks in the bark on their trunks. Over the course of last summer those trees died.

However, in spite of having cracks in its own bark, our tree has most of its leaves and appears to be growing well. Is there anything special I should be doing to help it this summer?

A: Keep it moist, and apply a high-nitrogen lawn food around it in the next couple of weeks, before it turns really hot (no weedkillers included). It sounds like it’s going to be fine.

Above all, don’t disturb the bark in any way. It’s probably forming a new layer of bark beneath the old, cracked bark. Let the old bark slough off on its own.

Q: We have just bought an older house that has two arborvitae shrubs flanking the front door. I’d like to prune them to open the entryway up a bit, but in looking into their centers, it appears there is no green growth inside the outer part. Will they come back if I do that kind of trimming?

A: No. That’s the short and simple answer. What you would be doing to them would be similar to what bagworms do to junipers and arborvitae when they strip off all of the needles. Conifers don’t really have the ability to send out new regrowth. The plants die instead.

In all candor, those plants have probably outlived their usefulness. Like linoleum countertops, their time has passed. Consider remodeling your landscape this fall. Spend the summer developing new ideas. It will probably feel great to do so. Fall is a fine time for planting.

Q: I have been using Dimension pre-emergent regularly for the past few years at the recommended times and directions and I am just not getting much benefit in preventing Poa annua in the spring. This year it has been even worse than ever. Is there another pre-emergent that might give better results?

A: There are several good ones (Dimension included). Halts and Balan are two others that I typically mention. However, in my experience, issues of improper timing and fall climate have caused poor performance more often than failure of any one of the pre-emergents.

Whichever one you choose it must be applied the last week of August or the first week of September if it’s going to prevent annual bluegrass. They are all granular, of course, and that would mean that you’ll need to water moderately soon after you apply them. Hopefully you won’t have a washing rain for the first couple of weeks thereafter.

The past couple of years have seen unusually dry and warm spells in much of Texas in September and October. That meant that the annual bluegrass season was thrown off schedule. You are not the only one who has reported poorer than expected results. Don’t give up.

Is you're trying to eliminate poison ivy from a shrub, it will take some time and you will need to work very carefully. Take care never to touch the leaves, stems or even roots of the poison ivy.

Q: How can I get poison ivy out of a large holly shrub? It sprouted up under the shrub, and before I knew it was there it was completely shrouding the bush.

A: You will need to work very carefully. Take care never to touch the leaves, stems or even roots of the poison ivy.

Honestly, the best thing to do would probably be to find the stem where it comes out of the ground. Use long-handled lopping shears or a pole pruning saw to cut the stem into two pieces.

Leave the severed vine to dry and die on top of the holly. It will turn crisp within a couple of weeks, at which time you’ll be able to use the lopping shears to cut the stems into small pieces so they can fall to the ground. Just leave them there until fall, at which point you can rake them up and discard them.

Finally, when the stump starts sending up new growth from the ground, reach in carefully and apply a broadleafed weedkiller containing 2,4-D with a pump spray applicator to the tender new growth. Be careful not to let the spray drift onto the leaves of the holly.

Q: I planted a Japanese maple on the west side of my house in April. Now I find out that they’re supposed to be planted in shade. I do have a good place for it in the backyard, but I also know that moving plants is supposed to be done during the winter. Would it be better to leave it where it is until then?

On a related note, what would be a good, purple-leafed tree for the full sun?

A: Do not leave it through the summer. When we talk about transplanting plants when they’re dormant, we’re talking about established plants where roots will have to be cut in the process of digging. Your plant has been there such a short time that it hasn’t developed any roots out into the surrounding soil.

Carefully dig around it with a sharpshooter spade and lift it up by the soil ball, not by its trunk. Have the planting hole ready in your backyard and replant it immediately. Be sure it’s replanted perfectly vertically. Pack the soil in gently around it, then water it slowly and thoroughly.

Forest Pansy redbud has intensely purple foliage in the spring. It shades to purplish-green by summer.

Add more soil as needed and use the excess to create a basin to retain water this first growing season. It should be just fine.

My recommendation for its replacement in the full western sun would be Forest Pansy redbud. It has intensely purple foliage in the spring. It shades to purplish-green by summer, but it’s still a great small tree with beautiful burgundy-colored flowers in spring.

Email questions for Neil Sperry to SAENgardenQA@sperrygardens.com.