“When is the best time to fertilize Rhododendrons?” Question from Carin of Fall Creek, Wisconsin
Answer: When it comes to questions about Rhododendrons and Azaleas, even experts like me turn to the American Rhododendron Society. Their goal is to teach gardeners how to make the most of these beautiful flowering shrubs. Their advice follows that of professional growers: if the plants look happy, perform well, and have fertile, well-drained soil that is slightly acid, then there is no need to feed them. Excess fertilizer can actually damage their roots. But, if your soil is sandy and poor, then I recommend amending it with Black Gold Peat Moss and Garden Compost Blend to increase water- and nutrient-holding ability. From there fertilize in the early spring with a food formulated for acid-loving plants, like rhododendrons. (Click here to read more.)
“I bought Black Gold potting soil with fertilizer for my herb, tomato, onion, and pepper seedlings. Do I also need to use liquid fertilizer once the seedlings grow their true leaves?” Question from Kim of Hiram, Ohio
Answer: It is important to be timely when fertilizing seedlings to give them the best head start. With that said, fertilizer in the soil can actually inhibit the germination of some seeds. (The salts in fertilizers disable the uptake of water in some seeds, which reduces or stops germination.) So, we recommend starting seeds in a mix that does not contain added fertilizer. Black Gold Seedling Mix is perfect for all types of seeds, and Black Gold Natural & Organic Potting Mix is a little coarser and great for starting larger seeds, like sunflowers, squash, and beans.
From there, start feeding seedlings with a 1/2 dilution of water-soluble fertilizer formulated for vegetables after they have begun to develop their true leaves. As they become larger, you can graduate to a full-strength dilution. I recommend waiting until they are 4-5 inches before feeding them fully.
“What is the best fertilizer for a grapevine?” Question from Deb at Lynbrook, New York
Answer: The truth is that grapes don’t require too much fertilizer if the soil is right. In fact, excess fertilization of vines encourages stem and foliar growth and discourages flowering and fruiting. Just picture an established vineyard in Europe. The grapes are old, stunted, and often growing in dry regions, but the oldest, most gnarled vines on the most well-drained soil produce the best wine grapes. Still, a little food is recommended on a yearly basis.
The more crucial factor regarding grape fruiting and success is soil type and drainage. First, most grapes prefer a slightly acid to neutral pH between 5.6 and 7, but some grape varieties also grow well at a slightly higher pH of 7.5. If soil pH is too acid or too alkaline, vines will experience various nutrient deficiencies, which will harm the growth and grape output. If your grapes have leaves that look stressed and unhealthy, I recommend you get a soil test for pH through Cornell Cooperative Extension (click here for more information).
Grapes also grow best in well-drained loam. Amending the soil at planting time with Black Gold® Garden Compost Blend and Canadian Sphagnum peat moss is recommended. Sand is another common amendment that will encourage drainage. Just make sure that your vines are planted where the soil drains quickly.