Enjoy Coleus in Three Dimensions by Training Them on a Trellis

Many people likely have the impression that coleus is a convenient foliage plant that colorfully decorates flower beds from summer to autumn. It is a very welcome presence that keeps showing off colorful leaf shades—red, yellow, copper, and variegated—even in midsummer when there are few flowers. Moreover, because it is relatively heat-tolerant and grows well in partial shade, it has been widely loved as a supporting player in summer flower beds.

In fact, thanks to recent breeding improvements, a wide variety of coleus cultivars are now on the market, and the ways to enjoy them have expanded significantly. While it used to be centered on seed-grown varieties, many excellent vegetative varieties that are propagated by cuttings have now appeared, and there is a rich variety in both leaf size and plant height.

Among these, I would like to recommend "trellis training" using tall-growing varieties. Raising the leaf colors three-dimensionally in a pot creates a gorgeousness that is different from flat container gardens, almost like a small wall flower bed. Being able to use space upward, even on a narrow balcony or at an entrance, is also a major appeal. This time, I will introduce, step by step, how to train coleus on a trellis, mainly using large and medium-sized vegetative varieties.

Coleus Varieties Suitable for Trellis Training

For trellis training, we mainly use large and medium-sized vegetative varieties that grow tall. Unlike seed-grown varieties, vegetative varieties propagated by cuttings have uniform characteristics, making them suitable for this type of training.

Basically, it is best to plant two or three varieties of the same color family together in one pot. Matching the color tones will keep it from looking cluttered and give it an elegant finish. Furthermore, by placing a different small or medium-sized variety at the base of the large variety to divide it into upper and lower sections, you can create a three-dimensional effect and a more gorgeous impression.

Let me give you some specific varieties. For large red varieties, there is 'Red Head,' and for large green varieties, there are 'Lime Sunshine' and 'Peter Green.' The 'Gorilla' series has both red and green varieties, so it is easy to balance colors within a single series, and the range of combinations is wide and easy to use. If you are placing something at the base, a small variety like 'Hot Beat' makes a perfect supporting player.

If you are unsure about color matching, the foolproof way is to start by grouping them by color family. For red, use different shades of red; for green, give the tones a range from lime to deep green so it doesn't become monotonous. Once you get used to it, it is fun to try bold combinations using complementary colors, such as using a small green variety at the base of a large red variety.

How to Train on a Trellis

Now, let's look at the actual training method step by step.

Prepare a pot of about 10 inches and a fan-shaped trellis. First, place pot-bottom stones in the bottom of the pot, and fill it about halfway with commercially available potting soil. Insert the trellis there, place the potted seedlings with their root balls lightly loosened on top of the potting soil, add the remaining potting soil, and press down firmly around the base of the plants.

When planting, the trick is to place the tall varieties toward the trellis and the short varieties in the front. This way, when viewed from the front, the gaze naturally flows from the low leaves to the high leaves, making it look well-organized.

The best place to put them is in a bright, semi-shaded area with good ventilation. Since coleus is a foliage plant, direct sunlight in midsummer is strictly forbidden. Be careful, as exposing them to strong sunlight will cause leaf burn and fade their colors. On the other hand, they like water, so be sure to give them plenty of water in midsummer so they don't dry out.

Vegetative varieties are less likely to develop flower buds, but if flower buds do form, cut them off from the base immediately. If you let them bloom, the plant will age, and the leaf color will deteriorate. As the coleus grows, fasten the extended stems to the trellis little by little, and prune the branches and leaves that stick out to the sides as appropriate to shape it. If you pinch the tips frequently, the number of branches will increase, and the entire trellis will be plumply covered with leaves.

Tips for Watering and Fertilizing

Since coleus is a plant that continuously develops leaves, it craves water and fertilizer. Especially when growing large plants like in trellis training, be careful not to let them dry out or run out of fertilizer.

The basic rule for watering is to give plenty of water once the surface of the potting soil is dry. During the midsummer season when sunny days continue, it may be necessary to water twice, in the morning and evening. Large varieties with big leaves use more water, so be careful not to let them dry out by mistake. Even if the leaves droop limply once, they will usually recover if you give them water immediately, but it is best not to let them dry out at all, as damaged leaves may appear.

For fertilizer, apply a slow-release fertilizer at the time of planting, and add liquid fertilizer about once every week to 10 days during the growing season to keep the leaf colors vibrant and the plant lush. If the leaf color becomes pale and blurry, it is a sign that the fertilizer is running out, so it is a good idea to add more.

By the way, in addition to the trellis training introduced here, you can enjoy various three-dimensional styles with vegetative coleus, such as standard training or tree training. Once you get used to trellis training, I think it would be fun to try these as the next step.

Midsummer Pest Control

By the way, coleus can suffer from pest damage if the plant weakens in midsummer. Be especially careful when it loses its vigor due to the heat and humidity.

If you find damage, first move it to a cool place before spraying with chemicals. If you spray a weakened plant while it is still in the scorching sun, it may end up being damaged further. It is better to boldly cut off the eaten leaves from the base. Rather than leaving damaged leaves, promoting the development of new leaves will help the plant recover faster.

Overwintering and Propagation

Coleus can be enjoyed outdoors until the frost hits, but it is weak against the cold and cannot overwinter outdoors. However, it is a plant that can be very easily propagated by cuttings, so there is no need to worry.

It is a good idea to make cuttings of your favorite varieties during the autumn. If you place the small cutting seedlings in a warm place indoors where they get sunlight through a lace curtain, they will survive the winter safely. And if you plant them again the following spring, you can enjoy your favorite varieties every year without them dying out.

Summary

The key to trellis training for coleus is to make the tall vegetative varieties the main feature and add small varieties at the base to build it three-dimensionally. As long as you keep up with management in partial shade and pay attention to preventing water shortages and humidity, you can enjoy a competition of leaf colors for a long time from summer to autumn.
Even in a midsummer garden with few flowers, coleus will colorfully and lively decorate it with its vivid leaf colors. Why not try decorating your coleus three-dimensionally with trellis training this summer?

Furthermore, in these days of advancing global warming, how to survive the summer is a major challenge common to all of us gardeners. If you would like to know more about summer management, please take a look at my book, 'Living Through Summer with Garden Plants: Summering Techniques for Gardeners.' You can read it at no extra charge if you have Kindle Unlimited.