Container garden will have large amount of potting soil at the end of the growing season. (Contributed Photo)

Dear Neil: Can I reuse potting soil I had in large containers on my patio last summer?

I normally do not, at least not in the same pots without taking it out and adding in “fresh” organic matter. Potting soil breaks down and compacts over the course of a growing season, so redoing it gives it new life. By the time you’ve done that a couple of times it’s time to use it in the vegetable garden or flower beds. That’s what I do with my own potting soil after I’ve used it just one year – I put it into my flower and vegetable garden. Their soils need improvements, too, and this year-old mix is better than anything else I could buy. Then I can start over with fresh potting soil in my large pots each year.

Dear Neil: What is the best way to trim my Asian jasmine? It really browned from the second cold spell.

I set my mower as high as it will go (almost 4 inches) and I carefully push it into one side of a bed to see what impact it will have before I commit to doing the entire bed. I trim mine often enough that it’s usually just about right, but if a bed hasn’t been trimmed for several years that might be a severe cut that would leave things looking really barren. Either way, the jasmine will come back very quickly. Apply a high nitrogen fertilizer and water it thoroughly. You may be amazed at how pretty it looks as it starts to regrow.

Your other alternative would be to use a gasoline-powered hedge trimmer to do the cutting. You’d have to rev it up to a fairly high speed to cut through the wiry stems, and it would wear your back out if the bed was very large. But if the planting has built up some depth it may be the only alternative. Line trimmers, at least in my experience, tug at the jasmine stems too much, pulling them loose in the process.

Dear Neil: I have had trouble growing Russelia (firecracker fern) in pots. They get full sun. I bring them in during cold weather. I keep the soil moist and give them fertilizer. They thrive in the ground where I grow them at our place in South Texas, but they’re puny in pots and never bloom. What could I be doing wrong?

Without a photo I’ll have to do a little guessing. This is a vigorous plant that grows to several feet tall (although it weeps, so it may not appear to be that tall). If your container plants are “puny,” it may be that the pots are too small and the reservoir of soil is too little to accommodate their water and nutrient needs. We end up watering plants in pots very frequently because of that, and that can leach nutrients out of the soil quickly. That would be my first guess. I’d also wonder about how hot the exposure was. Again, plants in pots can get much warmer when their root systems are exposed to the hot summer sun. You mentioned that you protect your plants during cold weather and that’s a good thing. Plants that are at all tender to cold lose about two hardiness zones of winter durability when their roots are left exposed to freezes in pots. You don’t have that much wiggle room with this plant. However, that doesn’t sound like the problem here. Other than those thoughts, without seeing the plants, I’m out of ideas.

Dear Neil: I saw a devil’s ivy plant with huge (dinner-plate-sized) leaves in a tropical botanic garden. How can I get mine to produce leaves that large?

That’s “adult” foliage, and it’s only produced on stems that are growing vertically. For home gardeners that usually means growing them on what florists used to call “totem poles.” When you see a plant that’s been trained in that way, you’ll notice that the bottom-most leaves are smaller than the top leaves. You’ll also notice that as the plant reaches the top of the pole and its stems start to droop past its support, the leaf sizes quickly decrease. Many years ago, my wife and I were on Maui near Hana. We were visiting the small cemetery where Charles Lindbergh is buried. The lane back to the entrance was lined with trees which were draped with devil’s ivy plants with leaves 18 inches across. They were spectacular.

As a side note, you’ll see a common Texas landscape plant, English ivy, (unrelated to devil’s ivy) doing a similar thing as it climbs. Its relatively small leaves on the ground, transform to larger, almost rounded leaves when they’re produced on vertical stems. That’s also the only place that you’ll see English ivy producing its clusters of flowers. It will never happen on the trailing juvenile growth.

Dear Neil: Does putting small rock across the bare ground beneath a live oak damage its root system?

No. They would still allow air and water to move freely into, and out of, the soil. The roots would be able to grow normally. Where we do damage is when we start adding inches of new soil and changing the grade beneath the trees. Soil compacts to inhibit that good movement of air and water. The stones do not.