|I recently bought some annuals and am not sure how much to water them. What else will these plants need in order to sustain good growth?|
|Since you didn't get any instructions, I'll start with the basic observation that while the marigolds prefer a bright sunny spot, the impatiens need partial to full shade and, in my experience, also seem to prefer extra moisture.
Annuals are fast growing plants that need a regular supply of moisture and nutrients. Exactly how often you need to water depends on the age of the plants and the weather. When they are young, just after transplanting, they'll need water more frequently than once they are older and more established. If the weather is hot and dry they'll need water more often than if it is cool. Some seasons in your area, rainfall will provide much of the needed water.
If your plants are in containers, you will need to water more frequently than if they are in the ground. Generally, water when the top layer of the soil is dry, probably every other day or so while the weather is cool, then daily and perhaps even twice a day by late summer when the plants are larger and the weather is truly hot.
Prepare the planting bed for annuals by working in organic matter such as homemade or commercial compost. After planting, mulch your plants with an organic mulch such as shredded bark. These two steps will help the soil conserve moisture and reduce water stress on the plants. They will also help keep your soil healthy as they decompose over time.
Prior to planting, mix 1 pound of a 10-10-10 fertilizer into 100 square feet of soil. Spread an equal amount 4 to 6 weeks later, or use a liquid fertilizer. Always follow label directions.
But you'll never know exactly how much fertilizer is optimum without having your soil tested. Check with your county extension office. They'll explain how to get it done, and then what the test results mean.