Dear Neil: We have several acres covered with poison ivy. Unfortunately, the ivy keeps spreading. Store-bought remedies as well as homemade mixtures have not worked. Do you have any suggestions?
You need to use something labeled specifically for control of poison ivy. That probably will be a broadleafed weedkiller (containing 2,4-D and perhaps two other herbicides blended together). I性视界传媒檝e used and recommended these products all my career and always with good outcomes if label directions are clearly followed. First and foremost, they work best on vigorous new growth. That means that you性视界传媒檙e just going into the prime treatment time.
Second, the best control will come if you coat the leaves thoroughly with fine droplets instead of a heavy spray that runs off onto the ground. Sometimes, on glossy-leafed plants, I性视界传媒檒l recommend mixing one drop of liquid dishwashing detergent per gallon of spray to help it hold onto the leaf surfaces, but that usually isn性视界传媒檛 necessary with poison ivy.
My wife and I bought our current homestead 50 years ago. It性视界传媒檚 a rural hillside on both sides of a creek. Large pecan and red oak trees cover probably 8 of the 11 acres. The remaining 3 acres were chest deep in poison ivy, honeysuckle, and smilax briars. It was a mess! The first thing I did, after we decided roughly where we wanted to build our house, was to hire a neighbor with a tractor and brush cutter to shred all the undergrowth. To my delight, almost none of the weedy vines came back after being cut to the ground. So that became Step One.
Step Two in our case was to cut all the poison ivy that was climbing any of our trees. I knew I couldn性视界传媒檛 spray up into the tree canopies because the herbicides would have harmed or killed the trees. I put on a long-sleeved shirt, cotton throw-away gloves, long pants, and boots. I used a long-handled axe, and I cut every ivy stalk near the ground line. (They can get as large as a man性视界传媒檚 arm.) I could have used a chain saw for this purpose, but the chunks of sawdust would have thrown oil all over me, plus it性视界传媒檚 more difficult to clean a chain saw of the poison ivy oil than it is to clean up an axe.
I made a second cut farther up on each trunk, then I used the head of the axe to pop the short section of stem out of the way. That allowed me clear access to the stump so that I could macerate it with the axe. I then poured the broadleafed weedkiller onto the pulverized stump surface at full strength so that it could soak into the wood and be carried down into the root system. That helped kill the roots to prevent resprouting and new growth.
I left the severed growth of the poison ivy up in the trees性视界传媒 canopies. I knew it would turn brown and be unsightly, but I also knew there was no way to cut or pull it out without a lot of close encounters with the stems and leaves of the still-oily plant tissues.
Since that time, for the ensuing 45 or more years I have used a garden hoe to eliminate any new poison ivy seedlings that have emerged, and I性视界传媒檝e cut any additional woody stems that I性视界传媒檝e discovered farther back into the woods.
And, from a completely different direction, you might even consider goats! You性视界传媒檒l see stories about cities 性视界传媒渞enting性视界传媒 herds of goats to clean up areas overrun with poison ivy, honeysuckle, briars, and other wild vegetation. They do a terrific job. Your local county Extension office would have an idea if anyone has such work crews available for rent.
Dear Neil: I have a splitleaf philodendron vine that has outgrown the pole it性视界传媒檚 on. I can find a taller pole, but I性视界传媒檓 wondering why its new leaves have fewer holes. They性视界传媒檙e not as large, and the plant isn性视界传媒檛 as interesting looking.
What you are seeing as the stem starts to hang downward is juvenile foliage. You性视界传媒檒l see the same phenomenon with our outdoor groundcover/vine English ivy. While it性视界传媒檚 growing horizontally its leaves are three-lobed and triangular. Once the stems start to attach to a tree trunk or the side of a wall or building, the new leaves are rounded and very different looking. A similar thing happens with devil性视界传媒檚 ivy (pothos). Its leaves get larger and larger as the plant climbs.
If your plant were mine, I would definitely repot it into a larger container. I would trim it to the height of the old support, but I would find a taller post so that its new growth could be encouraged to stay vertical. You could use the trimmings to propagate cuttings for new plants. Problems all solved.
Dear Neil: I have grown hoyas for years and I性视界传媒檓 always pleased when they bloom. However, I性视界传媒檝e never had these yellow spots on them before. What is this, and what should I do? (I have them outdoors for the summer now. They are in the house all winter.)
These are aphids. Curiously, hoyas are in the milkweed family, and you will see this very same (or a very similar) aphid species all over wild milkweeds in vacant lots and farm fields. They have piercing/sucking mouthparts, and the main 性视界传媒渄amage性视界传媒 they do is to exude a sticky honeydew residue onto the leaf surfaces. From that a black sooty mold can develop on the honeydew. I see a faint start of it on several of the leaves in your photo. I would use a stream of water to wash the aphids off. You don性视界传媒檛 want to use so much pressure that you damage the flowers, of course, so if the water treatment doesn性视界传媒檛 work, you should use an inorganic or organic insecticide that性视界传媒檚 labeled for control of aphids. In the meantime, you can also use a soft rag and soapy water to clean the mold off the waxy leaves.
