Trumpet Vine Slow Growth and Leaves with Red Spots

Q. I sent you some pictures of my trumpet vine which I planted as a small plant this last spring.  The plant has barely grown and the leaves have developed red spots all over them.  I believe it has a 2 gph emitter and watered three times a week for 20 minutes.

Red spots on leaves of trumpet vine.

A. Thanks for giving me such good irrigation information. From this I can estimate you are giving the plant about 7/10 of a gallon each time you water, three times a week. This is probably enough water for this plant when it is small but it will not be enough as it gets larger. If you cannot increase the number of minutes, then I would add a second emitter at the base of the plant.

Drip emitter at base of trumpet vine

            Trumpet vine is a hardy plant and thrives in most of the country where the soil is good and it gets plenty of water. It loves the heat. In fact, this plant can grow like a weed, extremely aggressive and in some places become invasive. 

            I don't think we have to worry about invasiveness here. It is not a desert plant so it will need a little bit of extra care.

            I see these red spots on leaves a lot with our fruit trees, particularly peaches. To me it is a sign of stress. There are two things that you should concentrate on to get this plant up and going and these focus on soil improvement and fertilizer.

Red spots developing on leaves of peach due to stress.

            This plant would benefit from improved soils sold applying a thick layer of surface mulch is going to make a big difference. I don't know what kind of soil improvement you made at the time of planting but this is a plant which would benefit from a lot of compost added to the soil at planting time.

            The organic surface mulch is going to help but I would put down a layer of compost near the plant and just under the mulch. You can get a load of free organic mulch from the UNCE Orchard in North Las Vegas. Once you have solved the soil problem, this plant would benefit with added water as I mentioned. 

            In late January or early February I would fertilizer with a decent landscape fertilizer and combine that with an application of iron. The best soil applied iron is going to be in the iron chelate form called EDDHA in the ingredients. Make sure it is applied to the drip emitters and watered in with a hose.

Peters fertilizer, a good quality plant fertilizer.

            In about March, spray the foliage with a good quality foliar fertilizer such as Miracle Gro or Peters. If you follow this advice, you will see some dramatic improvements.