Question: We have several bare areas where we want to plant something. We might be moving this summer, but maybe not until next year, so we don’t want to spend a lot. We have not had good luck with the packs of annual flowers in the past. How do we make annuals work?
Answer: Annual flowers are usually very easy to grow. They are, by definition, plants that need to be planted new each year. There are thousands of species that are very ornamental. You can also use plants that are long-lived, but do not tolerate a frost. Many of these tropical plants can be used as houseplants.
You said the areas are bare right now. Does that mean the soil is compacted and not even the weeds are growing? A temporary fix would be to dig a shovelful of soil, turn it over, throw on a half-shovel of compost and then use a tiller to mix it.
An even easier temporary fix would be to just use pots and containers, but that is not what you asked about, so let’s keep going.
First, you need to buy healthy plants that meet the sun and moisture conditions of the bare areas. If there are different conditions in each area, then different plants need to go there. If the bare areas are next to sidewalks or driveways that reflect the sun’s heat, take that into consideration.
Before you buy them, gently take the plants out of the pot and check the roots. They should be white, not brown and mushy. They should cover all of the areas of soil in the pot. If there are only a few, the plant has not been in the pot long enough, and if they are circling around and around, it has been in too long. The top of the plant should not have lots of dead leaves; one or two small bottom ones turning yellow is OK. The stem should not have soft brown spots or long gaps where there are no leaves.
Plants that are in larger pots do better than small pack plants. You will get a more immediate effect, and you will need fewer plants. It may be that you will also spend less overall because of this. Larger plants have more roots and so will not dry out as fast after planting.
Even if the soil is not too bad, adding a couple inches of composted organic matter will help the plants. A starter fertilizer of a slow-release type with a high middle number should be added according to the label directions. The bed should be damp when you plant into the soil. The plants should be watered the night before and planted in the morning. Water immediately after planting. The first few weeks are critical to the success of the annual bed. The roots of the plants must get out into the soil of the bed, but they can only do this if the soil is moist and not waterlogged or dry.
The plant must be set in the ground at the same level as it was growing in the pot. In other words, the soil level in the pot must be flush with the soil in the ground. If it is planted too low, the roots may rot; if it is too high, they will dry out. A thin layer of mulch over the top of the planting will help.
Annuals do make the most visual impact, so if you are selling the house, they may be the best type of plant to use. If it is your landscape, you could use perennials that can be moved to other locations. Tropical trees, shrubs, and houseplants all provide interesting color in flowers and leaves. Many of these plants can then be dug up and will do well in containers on the patio, taken indoors, or moved with you.