Annuals are among the most colorful and versatile plants in our gardens, and as planting season is upon us, I thought a few words on their care and use might be in order. By definition, an annual is any plant that comes from seed, goes through physical growth, flowers, sets seed, and dies all in one year. Annuals come in an unlimited number of colors and range in size from the tiny alyssum, which is two to three inches tall, to the giant marigold and otherspecies, which can grow to a height of three or four feet. Furthermore, once in bloom, annuals will generally stay in bloom until a fall freeze, providing they don’t gain too many mature seed heads. (This signals internally the end of an annual’s “mission”, but can be avoided by pinching the plant back and/or dead heading, which is the regular removal of seed heads – whichever is appropriate for your plants.) With annuals, you can maintain a yard full of color from mid-May to mid-October. Another year annuals could be started from seed in your basement so that you can be sure of the variety you want and some plants that are not usually grown commercially.
There are just a few things to remember when dealing with annuals to further your success with them: when selecting annuals for your garden, keep in mind their growing habits and cultural requirements, as well as their color, size, and leaf texture. Remember that annuals are like an artist’s palette since practically anything is available as far as size and color go.
There are annuals out there that require dry soil, moderately wet soil, high or bright light, or significant amounts of shade. If you are unsure about a particular variety, ask the folks at the garden center. The plants are frequently displayed in groups of plants with similar cultural needs. When buying annuals, choose the shorter, stockier plants of a kind when available. Also, buy early to get the desired type and colors and leave them in the flats or cell packs until safe planting time and warmer soil conditions. Be sure they get sunlight during the day and are sheltered at night, and once planted, keep blankets and/or old sheets or burlap on hand to protect them from a late frost.
If you’re careful, there will be very limited root damage when transplanting. To accommodate some root loss, pinch tops back at least an inch or so. This will also encourage side buds to open and continue to make this a short, fat, healthy plant. Next, water the entire flat or tray thirty minutes before planting. If you need to lay the plants out in your bed to properly space them, leave them out for only a few moments. You don’t want them to dry out.
As for spacing, you need to plant your annuals far enough apart so they can develop normally over the entire course of the summer. Just refer to the plant’s tag or ask a professional. Plants spaced too closely together will at least compete or even crush one another.
Immediately after planting, you need to water your annuals again. In fact, my best advice is to water them twice that day and thoroughly again the next day. After this, you can skip a couple of days and then, later, as many as five days between waterings. Initially, water just enough to keep the plant from wilting without drowning the plant either. To further prevent wilting those first few days, cheesecloth may be used as a shade barrier. If you have a choice, a cool and overcast day is ideal for planting.
Along with that first watering, I recommend adding a water-soluble fertilizer. Since there has been some root disturbance, I usually use only ½ the suggested rate. This should definitely be done by the end of the first week and then again only as the plants require. It is not uncommon to fertilize annuals every three to four weeks until fall to get and keep robust flowering going at all times. To keep plants shorter and bushier and prevent mature seedheads from signaling the end of the season, you should trim off one-third the height of most annuals around the first week of July. If you want to keep some color, do this in shifts of one-third or one-half the plants at a time. This will help keep the plants short and dense.
By following these few simple guidelines, you should see a wonderful landscape full of color clear through the first frost. This makes the time spent on your annuals well worthwhile.