Most gardeners begin their love of gardening with annuals. Planting them is therefore thought to be child’s play, and that is true, so long as one follows certain simple but sometimes overlooked practices. Here are the essential steps for getting annuals and other seedlings off to a good start.
Soil Preparation: Plants grow best in soil that has been loosened before planting to allow ready penetration of oxygen and water. A shovel, spade, or rototiller works well for breaking ground, turning the soil, and chopping up clods; a rototiller comes in handy for preparing a large area. Spread 3–4″ of organic matter (such as compost, peat moss, well-rotted manure, or leaf mold) over the area to be prepared, then turn it into the soil to a depth of approximately 10–12″. We get good results by digging down just one shovel’s depth, and unless your soil requires extensive rehabilitation, you probably will, too.
Planting: Your plants are fresh from the protected environment of a greenhouse and they need a gradual introduction to direct sun and stiff breezes before planting. Set plants outdoors in a sheltered, lightly shaded spot, increasing their exposure to sun and wind each day. At the end of one week (give or take a day or two), they'll be ready to go in the ground.
Before planting, check the moisture of the potting mix. Water thoroughly if it's dry. Then dig a hole just slightly larger than the pot. Remove the plant from the pot by grasping the rim, turning the pot upside down, and tapping it against the heel of your hand. If the plant is root-bound (the root ball matted with roots to the point that they all but obscure the potting mix), gently break up the sides of the ball with your thumbs and tease apart roots that are circling at the bottom. This operation encourages the roots to grow out of the potting mix and into the surrounding soil. Set the root ball in the hole so that the top of the ball is level with the surface of the soil. Then push soil around and just over the top of the root ball, firm the soil, and give the plant a thorough soaking to settle the soil.
Watering: The key to getting a new plant off to a good start is moisture. Water thoroughly after planting, and keep a close eye on the plant over the following week. If you see it wilt on a hot, sunny day, check the soil to a depth of about 1″. If dry, water thoroughly. If the soil below the surface is moist to the touch, don’t water. The plant is probably wilting because the roots are unable to supply the top with sufficient moisture even though the soil is damp. The remedy is to contrive some means of shading the plant. Within a week or so, the roots should catch up, and you can remove the shading.
After the first week, give a new plant a good soaking once a week during summer, unless there is more than 1″ of rainfall per week. Established plants can get by on less water, but most grow best if the soil remains evenly moist. Please note that more water is not better. When in doubt, don’t water.
Fertilizing: We recommend scattering a timed-release fertilizer around the feet of annuals at planting time or applying a water-soluble fertilizer (such as 20-20-20) at half or quarter strength. When plants are established, apply the fertilizer, mixed as directed, every other week in summer.
Gardening in Containers: Plants in containers need special care. They dry out more quickly than plants in the ground; in the heat of the summer, you may have to water them daily. Because of the need for frequent watering, nutrients soon wash out the bottom of the pot. We recommend you use a potting mix specifically designed for use in containers, and incorporate a timed-release fertilizer into the potting mix before you add the mix to the container. In addition, to keep annuals growing and flowering in summer, we recommend that you water with a balanced, water-soluble fertilizer (such as 20-20-20), mixed and applied as directed. Finally, to look their best, most plants in containers need regular grooming. Remove spent flowers regularly and prune vigorous growers to keep them in check.