Q. My wife and I have 20 hanging baskets on our deck. This year we used trailing petunias. They started out very nice but as the summer went along, they got really spindly and didn’t produce any blooms to speak of. We intend to use petunias again next year. Can you suggest what I can do differently to produce healthy, vigorous plants that trail and bloom? We see huge baskets hanging around our town with thousands of blooms. Thank you. Ron Wilhelmson – Gig Harbor, WA
A. Without information on your care regimen or the exposure of your deck I can only make general recommendations as to how you can be more successful next year. If your deck is in the shade you may want to consider a shade tolerant annuals like begonias, browalia, or impatiens, instead of trailing petunias, which prefer full sun. Petunias will become leggy and not bloom if they do not receive enough direct sun during the day. I would suggest a minimum of six hours direct sun a day. If the plants are receiving sufficient sunlight then you will need to keep them well watered. Smaller hanging baskets can require daily watering during our summers. Some days they may require water twice. Trailing plants are especially susceptible to drying out because the surface area of the root system and the water holding capacity of the soil is limited by the size of the pot. As the plants grow and trail the leaf surface area continues to increase as the summer progresses. This means more water is used and transpired from these leaves than the limited soil and root system can support. Another consideration is the plants nutrition over the course of the summer. Soilless mixes are the norm in hanging baskets. This means that there are limited nutrients contained in the container. The plants depend on you to provide their nutrients. You can provide a diluted fertilizer in each watering, fertilize every two weeks during the growing season (in both cases with a water soluble fertilizer) or apply a balanced slow release fertilizer at the beginning of the season. Most slow release fertilizers will provide nutrients for 3 months. Use a fertilizer made for growing in containers, or for flowering plants. If you are growing the plants in a soilless mix be sure that the fertilizer provides primary (nitrogen, phosphorus, potassium), secondary (calcium, magnesium and sulfur) and micronutrients (iron, manganese, copper, boron, zinc and molybdenum).