Written by Barbara Gee
Incorporating annuals into your garden designs is great fun. You get a lot of “bang for your buck.” Most annuals flower throughout the summer and really take very little care once established. And they come and go in one season so you can change your color palette, shapes and textures every year.
An annual is a plant that goes through its life cycle in one season from germination to setting seed, and finally “expiring.” People often get confused between annuals and biennial. “Bi” simply means two, so a biennial like foxglove or hollyhock goes through the same cycle over a period of two years. Biennials often spread seed profusely and so new plants pop up making it look like the original plant never died.
Choosing Your Annuals
Most annuals like full sun and most are easy to grow. There’s a wide variety of choices in color, size, texture and foliage – and, of course, there are annual vines too like Black-eyed Susan vine, or Cardinal climber. And a few annuals will tolerate some shade like pincushion flower. Certain annuals, like coreopsis, should be sown directly into the soil outside. Others, like petunias, need to be started indoors. Different annuals require a different amount of time to germinate – for some, like ageratum, it can be less than ten days, while others like gerbera may take up to three weeks. The seed packet will usually have this kind of information.
To garden economically know what you want to buy before you head for the garden center. It’s way too tempting once you get there and are faced with all the choices. Keep in mind the purpose for which you want the annuals – containers, cutting gardens, in a border… and take into account the garden conditions you have – sun or shade? And some annuals need a rich soil while others like nasturtium actually prefer a less fertile soil.
Look for plants with strong stems and healthy leaves – not wilted or yellowed. Check the roots – they should be moist, white and fairly loose in the soil. Even knock a plant gently out of the pot to check.
If the plants are in bloom you may want to pinch them back when you get home to help them grow stronger roots and bush out. If the soil in the pot is excessively dry it may show that the garden center hasn’t been diligent about watering.
Starting Annuals
Whether you sow seeds indoors or outside, the date you start should be determined by the last frost date in your area. Work back from that date calculating the number of weeks to allow for seed germination and for the plant to be strong and healthy enough to be planted outside.
Use flats or individual pots and a good soilless seed-starting mix which should be moist – not wet. Most seeds are sown at a depth equal to three times their diameter. Some need to germinate in the dark and some in the light. For the first cover the pots with a lid or put them in a dark cupboard. For the others just press the seeds lightly into the mix.
Warmth and moisture are required for germination. So create those conditions by covering the pots with a transparent lid or plastic wrap. Check regularly to make sure conditions are not too wet, and lift the lid to let air in. When they sprout take the lid off to allow them to grow.
You need a good source of light. Put the pots on a very sunny windowsill and turn them every day. Or use a fluorescent “grow-light” setup. Keep the soil moist, not wet.
If you see the fungal disease “damping-off” you may lose some but not necessarily all the plants. The seedlings will wilt and collapse. Damping-off travels quickly so eliminate the affected plants and increase ventilation.
Seedlings that have developed their second set of leaves can be transplanted into individual pots. Peat pots are a good investment because the entire pot can be planted and the pots decompose. Some plants like nasturtium don’t like to be disturbed so planting them in the pot or directly in the ground minimizes the disturbance.
Planting and Care
Plants that have been grown indoors will need to go through the process of “hardening off” to prepare them for life outdoors. This simply means getting them used to being outside. You can do this by putting the plants outside for a longer period each day bringing them in at night, until such time as they can be left outside all night. They can then be planted.
Good soil is key to successful gardening and cuts down on your need for extra fertilizer. A good slow-release fertilizer at the time of planting should do it, but you may want to add some more occasionally through the summer. Just remember that some prefer a lean soil. Read the literature to find out. Mulching helps retain moisture and prevents weeds from taking hold.
Annuals need basic care once in the ground.
Deadhead the plants – this means removing spent blooms which helps the plant put energy into new blooms. It also makes the plant look nicer.
End of the Season
As the first frost approaches, you can harvest and save seeds. Harvest the seeds when ripe which is usually when the seedpods or capsules turn brown and dry.
When you are closing up the garden for the winter you can either pull out the spent annuals or cut them back to the ground leaving the roots to decompose in the ground.
Clear your garden debris away so that you don’t create a habitat that encourages insects, pests, or diseases. Removing debris also makes it more difficult for insects to overwinter.
And always remember to enjoy your garden work.
A Few Choice Annuals
Love-lies-Bleeding (Amaranthus)
Cockscomb (Celosia argentea)
Basket flower (Centaurea americana)
China Pink (Dianthus chinensis)
Lupine (Lupinus luteus)
Forget-me-not (Myosotis sylvatica)
Snapdragon (Antirrhinum)
Milkweed (Asclepias)
Arctic Poppy (Papaver croceum)
Sunflower (Helianthus)
Black-eyed Susan vine (Thumbergia alata)
Cardinal climber vine (Ipmoea x multifida)