“The first year they sleep, the second year they creep, the third year they leap.”
In a leap year — or any gardening year — this old advice is worth remembering. “It tells you what to expect from new plants, whether they’re trees or shrubs or perennials,” said Spencer Campbell, Plant Clinic manager at The Morton Arboretum in Lisle.
When perennial plants, including woody plants, are transplanted, they typically don’t show much visible growth or bloom in the first season. The next year, they often grow and flower moderately. It’s usually not until the next year that they really take off.
The reason is simple: A plant needs to expand its root system before it can support the growth of stems, branches, leaves and flowers. Since all the water and nutrients the plant uses must come in through its collecting network of roots, vigorous growth above ground has to wait until the network can provide enough resources.
“New plants may look sparse in the first year, but they actually are growing,” Campbell said. “They’re just growing underground, working on their root systems.”
For that reason, when you plant trees, shrubs and perennials, they won’t immediately look much like their pictures in plant catalogs or on labels. “How long it takes them to get established will vary depending on the kinds of plant,” he said. “But they all need some time to settle in and extend their roots before you see them growing toward their mature size.”
Here are some tips for establishing new plants.
Mind your spacing. Even if new plants seem small or spindly, resist the temptation to place them too close together. “The spacing given on the plant label allows for the mature size,” Campbell said. “If you don’t follow it, the plants will be crowded once they do start growing vigorously.”
Mulch. Cover the area around any new plant with an organic mulch, such as chipped or shredded wood or dry leaves, to hold in moisture, moderate the soil temperature and encourage root growth.
Water. Because they don’t yet have much of a root system, new plants need extra attention to be sure they have enough water available. “Check the soil in the planting area often to make sure it stays moist,” he said.
Fertilize with restraint. A little slow-release fertilizer at planting is fine, but don’t to try force new plants to grow faster by extra fertilizing. “That will only force the plant to grow leaves at the expense of roots, which will hold the plant back in the long run,” Campbell said. Most trees, shrubs and perennials can gather enough nutrients from good soil that is rich in organic matter without added fertilizer.
Use annual flowers for temporary color. While new perennials are still small and widely spaced, fill in between them with annual flowers or foliage plants such as coleus, planted either in the ground or in containers. “If you have a plan for what you will do until your perennials and shrubs fill out and bloom, it can help you avoid the temptation to plant them too close together,” he said. Many kinds of annual flowers, such as cosmos, zinnias, marigolds and lantana, are attractive to pollinating insects. Some, such as sunflowers, provide seeds to feed wildlife.
Manage your expectations. Be aware that even trees and shrubs marketed as “fast-growing” will take some time to be established. “There are no instant hedges,” Campbell said. Choose trees and shrubs in view of the mature size they will reach, not just their growth rate.
Plan for the long term. “Plant as an investment, and know it will take some time to pay off,” he said. “Patience is an important ingredient in any garden.”
For tree and plant advice, contact the Plant Clinic at The Morton Arboretum (630-719-2424, mortonarb.org/plant-clinic, or plantclinic@mortonarb.org). Beth Botts is a staff writer at the Arboretum.
