In midsummer we often experience container plantings that look terrible. The petunias look stringy and bedraggled, the coleus plants are overgrown and the calibrachoa stopped blooming long ago. Our plants are suddenly overgrown or seem to have stopped growing altogether. You feel like you have been doing everything right, watering every day, new potting soil this year, proper light requirements and still they are letting you down.
The underlying problem is often that annual plants were pampered while growing in the greenhouses where we bought them. There are 3 basic cures for most annuals in our own home conditions: pinching, fertilizing and watering.
Pinching is a user-friendly method of controlling annual growth habit. This means you remove the tip of the main stem, cutting it back to right above the next set of leaves on the stem. This forces the plant to send out new side shoots, (lateral growth) and keeps it compact. It is a good practice to pinch almost all of our annuals when we plant them. This ensures the first flush of new growth will be bushy and well branched. After flowering, pinch back the spent flower buds to quicken the plant’s production of new flowers. For foliage plants, removing the flower buds before they open is a great way to force the plant to produce new leaves.
Fertilizing is often done in greenhouses at every watering, which means that plants are receiving supplemental nutrients every day. Most home gardeners fertilize only a few times throughout the growing season, or not at all. Unless your annuals are exhibiting signs of nutrient deficiencies (mainly leaf discoloration), they will be fine with consistent fertilizer from a natural source. A fertilizer with low amounts of each nutrient (NPK) can keep your annuals growing up to their potential, like an 8-2-5 or something similar.
Watering is often the most obvious answer to why annual plants crash prematurely. Unfortunately, the symptoms of overwatering are very similar to those of underwatering, so it is deceptively easy to over-correct and water a dry plant way too much. When you water, the entire rootball of the plant should be saturated by the time you’re finished. Water should be draining out of the bottom of the container when it’s soaked through. Make sure, though, that the root ball is not so hard and dry that the water is just running down the sides rather than soaking through the whole area. For annuals planted directly into the ground, give them a good thorough drench that permeates into the surrounding soil. Then, be very sure the soil is dried out before you water again. The top few inches of soil should be dry to the touch before you re-water.
Maintaining annual plantings requires vigilance and a little detail work, but it’s very much worth it!