Before planting, test your soil’s drainage. Dig a hole 1 cubic foot and then fill it with water. If the water has fully seeped into the soil after 8 hours, your drainage is adequate. If water still remails, you may have to do one or all of the following: Make sure you have positive pitch across the surface of the plant bed area. If not, re-grade area to establish at least 2% pitch (2′ depth over 100′ run). The area in and around the plant bed may need amending. This can be achieved by rototilling in 1/4% compost to a depth of at least 8″. You should also amend soil 6″ below root ball and at least twice the distance of the root ball on all sides. Adding 1 cup of horticultural perlite per 1cubic foot into existing soil will also be helpful.
Ensure moisture has penetrated deeply into the root zone. Watering once or twice a week is enough. Avoid light watering that only wets the topsoil and doesn’t reach the root zone. Check soil moisture by digging about 6 inches down, away from the plant roots. If soil is dry and powdery, it needs water. Well-watered soil should stick together when pressed into a ball.
Proper watering is essential for plant health, but too much of a good thing can cause significant problems. Even in dry spells, over watering can lead to root rot. Marigolds, verbenas, hollies, boxwoods, azaleas, and rhododendrons are particularly sensitive to root rot. And when the rain returns, don’t forget to adjust your watering accordingly.
For those with automatic irrigation systems, set them to water for longer periods of time, but less frequently. Deep infrequent watering encourages deeper root growth and healthier plants. Adjust the schedule based on rainfall and temperature. If you don’t have a water sensor, installing one is highly recommended. They are inexpensive and provides insight on water saturation, thus saving water over time. By regularly checking and adjusting your irrigation system to ensure the right amount of water and moisture retention, you can avoid the problems that come with overwatering.