Another crocosmia question

Asked July 17, 2019, 6:24 PM EDT

I was trying to find out why my crocosmia isn't blooming. A little backstory about it. I gleaned s small bunch from the central Oregon coast. I live in the valley, but crocosmia bloom all over here as well. I've had it in my garden for about five years. It's bloomed once or twice, but nothing like what it should. This year (and last) it gave me no blooms at all. It's mid-July and I see them in full bloom everywhere, and I'm so sad and jealous. I've divided it once, but the division aren't blooming either. The main one is a huge mound, probably 3 feet wide. How can something so big and beautiful not bloom?

Linn County Oregon crocosmia horticulture

1 Response

Hi and thanks for contacting Ask an Expert.
Since you have had these for so long and have divided them, it may be a lack of phosphorus and other minerals in the soil. As you said, you have lush green growth, which means it is in a good location and getting the right amount of sunshine and water.
You can add a liquid fertilizer that is specifically for encouraging flowers to form. There are several on the market. I use Liquid Bloom which is mixed with water and I water it in especially in July as most of the flowers have given us their spring blooms and those are fading.
The plant probably needs more phosphorus and possibly calcium. Also you can add bone meal (dried powder) around the plant and gently dig it in then water the plant. After you water it in, mix the bloom fertilizer and drench the soil.
The three numbers on the package or bottle usually look like: 3-6-3 or 5-5-5 or really any combination. The first number is the amount of nitrogen in the fertilizer, the second is phosphorus and the third is potassium. You need the phosphorus and there are fertilizers that say 0-5-3 or similar numbers. The Bloom liquid is 0-6-0. this means there is approximately 6% of phosphorus in the amendment. The bone meal will take some time to absorb into the plant but the liquid with the soil being wet, should absorb pretty quickly.
The reason I use 0-6-0 is to promote blooms. If the first number (for nitrogen) was there it would add to the lush green plant and not the flowers. You want to focus the plant on making blossoms.
However, that said, you will need to be patient. Continue with the liquid Bloom as directed on the package. Add a mulch around the plant to keep the soil moist, they do not like to be in dry soil.
The only other thing that may help is to divide the big clump once again in the fall. However, adding the amendments I mentioned will probably give you blooms. What you do this year, will also affect the plant next year. When the plant starts to die back you can cut the leaves and mulch over it. Letting leaves compost over the winter will add more nutrients to the plant next spring.
If you have further questions, please re-contact us. Good Luck.