by Larry Hurley, Perennial Plant Buyer

Or, perhaps we should say Tuin Up; I believe Tuin is Dutch for garden. By mid-summer, much of your garden is feeling a little dragged out. Hot days and warm nights are tough on plants as well as people. A little pruning back can be just the ticket to rejuvenate annuals and perennials. I’m not your guy for vegetable garden hints, I have a shady yard.

Let’s start with hanging baskets. A couple of things happen over time, both a factor of the concept that, if a plant is still alive, it’s trying to grow. (That which doesn’t kill it, makes it longer.)

Hanging Baskets: Basket plants should be sheared or selectively pinched to keep them in proportion to the pot. Petunias, for example, will trail down the side of the pot, growing and flowering from the ends of the stems, until you have flowers at the end of 18 inch long stems with few leaves or flowers at the top around the basket.

The best thing to do is selectively cut off about 20% of the stems each week or two right at the edge of the basket. As those stems recover and start to grow and make flower buds, you cut the next 20%. Over time, you keep the plant to a manageable length and it never looks like it was cut back. For an upright plant, do the same thing–just pinch random stems back from say 12 inches long to 4 inches long, once every week or two.

As the basket ages, the plants roots slowly fill the soil in the basket. The soil settles, washes out of the pot, decays…at some point you have more roots than soil. Roots don’t hold water like soil does. If you find you are watering a couple of times a day, it may be time to put the plant into a larger container– maybe no longer hanging– or in the ground.

Echinacea Trial garden

Perennials: The best reference is The Well-Tended Perennial Garden, by Tracy DiSabato-Aust. She tells you how and when to cut back or shear plants in your perennial garden in order to control height, or to prepare the plant for another surge of bloom if it’s a rebloomer like most of the summer-blooming perennials are. Tracy is a landscape contractor in Ohio, and the book is written from practical experience and for the average gardener.

Annuals: Cut off old flower heads to encourage rebloom (deadheading) or cut back the plant part way to encourage bushiness and branching (and eventually more flowers). If you are happy with how they look, don’t do anything. Vinca and Supertunias probably don’t need any attention at all.

Herb Container. Photo by Larry Hurley

Herbs: Continue to pinch off the ends of the stems to encourage bushiness. With basil, remove flower buds by pinching out the flowering stems. If you have a few strong stems that have not gone to flower, take a 3-inch- or-so long tip cutting (the end 3 inches of the stem) and put it in a glass of water so that the bottom inch or so is in the water and the top is in a sunny window. It should root in about 10 days. In two or three weeks, you can plant it back outside while your older basil flowers and declines. The water glass should be dark; dark colored, or wrap it in foil. You can do that with coleus, too.

Weeds: Pull them out, they are just going to get bigger and meaner.

Simply Put: Annuals

In the horticultural world, there are three major groupings of plants intended for planting outdoors: annuals, perennials and woody plants. The differences blur a little bit because horticulturists are a more relaxed group of people than botanists, who tend to be very serious about this sort of thing. And the garden center strain of horticulturist tends to be so relaxed that we slump.

Just for the record, botanists are the basic science folks. They worry about things like what plants grow on some ledge in Patagonia and who first named them in 1712. Agronomists are applied science folks that work with field crops (wheat, corn, alfalfa) and horticulturists are also applied science folks that work with the small scale stuff—vegetables, fruits, and ornamental (decorative) plants. We’re the frosting on the cake.

So: first. Annuals.

Annuals are plants that are programmed (Mother Nature 3.0) to live their entire lives in one year (an annual life cycle). That is, they start out as a seed, grow, flower, make more seeds to start the next generation and die, all within one year or less. In the garden center, some plants that would live for more than a year in a warmer climate are sold as annuals because they croak when it gets cold (begonias, for example) or hot (pansies). So, for your purposes as a garden center shopper, you get one growing season out of an annual, and if you want to use it again next year, you have to replant.

The primary advantage to annuals is a long blooming season. A petunia planted in May should still be blooming in September. You want to plant something in a shady spot and have flowers all summer? You must plant an annual. When shopping, you will find annuals that flower well in cool weather—they may tolerate some frost–or hot weather, but not both.

When we in the garden center biz are talking about annuals we are talking about Flowers. Although vegetable plants are often annual in behavior, we just call them “vegetables.” Herbs may be annual (basil) or perennial (thyme), but we sell them by use, which is “herbs.” A bonus to you as a customer: people selling annuals (and vegetables) don’t get real hung up on Latin names. So, you can safely walk up to someone and ask for a marigold and not have anyone get snooty about it.

Because they are so colorful and relatively inexpensive to boot, garden centers sell more annuals than anything else–usually as started plants–although many annuals can be started as seed sown directly into the garden. (Some of the newer annuals such as Wave Petunias or Supertunias are grown by specialist growers from cuttings instead of seed.)

Annuals look best when planted in groups for big blocks of color, mixed or as a single variety. Gardening with annuals became popular in the late 1800’s. The practice of planting annuals in flower beds was called “bedding out,” and gave rise to the term “bedding plants” which is still used as a synonym for annuals.

Next time: perennials, woody plants, and biennials.

Ornamental Cabbage and Kale
By Larry Hurley, Perennial Specialist

Ornamental kale is becoming increasingly popular with gardeners looking for a cool-season ornamental to compliment pansy plantings. They are at their best in late Fall, and depending on the weather, may look good into the following Spring. Round-leaved types are called ornamental cabbage, while lacy-leaved types are called ornamental kale, but generally we use the generic “ornamental cabbageandkale” as the culture and uses are the same.

According to Gerald Klingaman of the University of Arkansas, “kale” is the Scot’s version of “cole”, the Roman term for the vegetable, which originated in the Mediterranean area. (Giving us the term “cole crop” for the kale/cabbage/broccoli vegetable group, “cole slaw” and so on). It eventually made its way to Japan, where people selected colorfully-leaved plants for ornamental purposes. Ornamental kales were brought to the United States in 1929 as a result of a USDA-sponsored collecting trip to Japan, and they first appeared in US seed catalogues in 1936. Most cultivars sold today were bred in Japan, and there are called “leaf peonies.”

Cool weather is required for good coloration. According to the University of Massachusetts, temperatures below 50 degrees cause the loss of chlorophyll, which allows the underlying purple, pink and white coloration of the leaves to become more prominent. Very cold temperatures in winter or heavy snows will tend to shorten their ornamental life. Some years, they look good into April, while other years they are pretty ratty by Christmas.

They are biennials, which means that they have leaves the first season, then form a flower spike in the spring.The yellow-flowered spike is generally considered to be of minor ornamental value. Ornamental kale and cabbage are quite attractive when planted in autumn mixed containers with pansies and ornamental grasses, or when used en masse in the ground with pansies. Like bulbs, they are less attractive when planted in rows like frilly little soldiers.Ornamental kale is available at our garden centers in early to mid-September, but will be more colorful at the end of the month or in early October. Be sure to watch for it and add it to your fall-color palette!