Question:
I want to be more successful in growing Alstroemeria. So far, I've had mixed results. Most die. And those who survive don't bloom much, growing tall and leggy. They are planted in a sunny location, and I keep them moist. However, I'm not sure on how and when to prune them. What must I do to be more successful?Answer:
- Alstroemerias are native to South America, where they're grown as a wildflower. Today, they are a major cut flower worldwide and are now being included in perennials and cutting gardens.
- Alstroemeria enjoys a sunny location with regular fertilizer applications and likes to be kept moist, but the soil must drain adequately. With our clay soil, you need to generously amend the soil with homemade compost, soil conditioner, or other organic matter to improve the drainage.
- Alstroemerias have many fleshy stems and roots, so the original root ball must be placed high out of the ground; a half an inch is sufficient. They usually struggle or die when planted too deep. This may be the key to solving your poor results. It will also be necessary to add mulch around the plants when the temperatures are eighty degrees or above. The foliage will turn ugly and look terrible when the plants go dry in between waterings. When this occurs, you cut the entire plant down to about four to eight inches and increase the frequency of your waterings. Pruning in the early spring, before the flush of spring growth, and again after each blooming period keeps them from getting leggy.
- Newly purchased plants will always be more compact and bushier than those in the ground as they are treated with a growth inhibitor to keep the plants from getting too leggy.
- Over the past several years, several new series of Alstroemerias have been introduced that are genetically dwarf plants. These plants stay naturally short, which makes them excellent in containers.
- The spent flowers and/or seed pods need to be removed often for repeat blooms. Alstroemerias have two types of growth. The first to appear is what I call grassy growth. It doesn't produce any flowers. This growth is shorter and thinner than the flower stems that come up later.
- If you have too much of this grassy growth, you can just thin it out by pulling it up. Not all of them, of course. If you look carefully at a plant with flowers, you will see that the flower stems are taller, thicker, and have more space between the nodes.
- The nodes are the place where tiny leaves come out, and of course, they have flowers. You remove the flowers by either cutting them off with a pair of scissors or pruning shears or by pulling the flower stem straight up.
- Snails and Slugs pose the biggest pest problems, so bait monthly through October. In conclusion, I'd improve the drainage with more organic matter and raise the plants so they are not buried and mulch.