This spring I planted my window box annuals using Miracle Grow Moisture Control Soil. Many of my plants ( mostly coleus) have been going limp and I feel the roots are getting bogged down by to much moisture. The boxes face west but we have not had a lot of sun or heat recently. I don't think I have over watered them but it is hard to tell as the soil never really feels dry. Also, the plants don't really seem to be growing. They have been in the window boxes for about one month. Would it be safe for the plants under the circumstances to take them out of the boxes, change the soil and then replant or would it be to stressful for them? The soil is always damp and I can imagine what it must be like down by the roots. Unfortunately I am not home to take a picture. Any advice would be very appreciated!! Thank you, Ann G.
In this situation, yes, it would be best to remove the plants and then replant after the soil has been changed. First, do your window boxes have drainage holes in the bottom? If they do not, you may wish to consider adding some drain holes using either a hammer and nail or a drill. Secondly, are the holes clogged? To help prevent clogged holes, you can place a piece of window screen or mesh over the holes. Thirdly, add a layer of gravel, broken terra cotta pot pieces, or even wadded up newspaper to the bottom before adding soil. This will assist with draining. Fourthly, add some sand or vermiculite to your soil to loosen the soil and help it to drain better. After this has been done, you can replant. Before watering, be sure you check the soil first by feeling the soil with your fingers. Insert your index finger about one inch into the soil. If it feels moist, do not water. You can also check the moisture level by using a moisture meter, if you so desire. Your plants should show improvement after a couple of weeks.
Here are two articles that you might find helpful: