Perennials Sleep, Creep, then Leap

Have you planted perennial plants or shrubs and thought you were doing something wrong since they weren’t growing? Maybe you added more plants the second year since you wanted to fill in the space and ran into problems later. Some perennials go through the phenomenon that has been coined with this saying, “The first year they sleep, the second year they creep and the third year they leap!”

When I worked at the extension office, I planted three abelia plants for a Monrovia trial in August 2016. I measured the plants weekly and noticed that the plants didn’t change their height and width for the entire year. The next year, their width tripled. Although I wasn't there for their 3rd year, I expected that it was truly sensational.

Why do perennials sleep, creep, and leap?

The first year you plant some perennials, vines, shrubs, and trees they may do nothing up top. This is because all their energy is focused on growing roots. By having well-developed roots, plants can find and take up water and nutrients easier, anchor the plants, and better resist pests and diseases.

The second year the plants creep. The roots grow bigger and stronger and you have more leaves, stems, and flowers than the previous year. With more leaves, the plant can create more food that is stored in the roots and throughout the plant. This is the normal progression unless something happens like a drought, freeze, or flood, which may affect the life of the plant.

Several vines do this pattern including passion vine, clematis, Dutchman’s pipevine, and several others. These vines should be supported with a trellis.

My Dutchman’s pipevine (seen in the photo), a larval food for pipevine swallowtails, remained its nursery size last season. The caterpillars didn’t find it since it was so small. They may have killed it if they had. This year the leaves halfway covered the trellis and a couple dozen caterpillars hatched. They completely devoured all the leaves but with a strong root system, the leaves should grow back.

It is during this second year that gardeners often overbuy plants to fill in the gaps. This can cause more harm than good.

When you plant perennials, you need to look at the overall size that the plant will grow and plant it according to the planting requirements. If you plant them too close, the plants will get crowded later and are more likely to be stressed and susceptible to diseases and insects. Unless you are planting annuals, don’t expect your landscape to really fill in until year three.

During “leap” year, plants really get to show their personality. Their root system is strong and most of their energy is put into the leaves and flowers. They really start to fill out, practically bursting with joy.

This is the best time to transplant them since you know what their overall size will be, especially if they are too large for their space. Unfortunately, it is also more difficult to dig them out because they are bigger with larger root systems.

Many plants peak between years three to five and remain like that for many years. Others may decline after five years. This signals that they need to be divided and given more room. This commonly occurs with plants such as blanket flower, coneflower, and daylily.

Some perennials that commonly sleep, creep, and leap include Adam’s needle, ornamental onion, milkweed, asters, lilies, ornamental grasses, old garden roses, irises, and many others.

Many shrubs also follow this routine. That is why when people ask me that they want a hedge that grows quickly to block out the neighbors, I have few options for them. There are many great shrubs that can be a hedge, but it takes time.

Perennials are great garden-friendly options and can look fantastic, in a few years. By giving them enough room and planting the right plant in the right place, you can reduce the amount of fertilizer, pesticide, and water to your landscape.