Ask Mr. Smarty Plants

We are also puzzled as to why your Crataegus marshallii (parsley hawthorn) is not blooming. We have some theories, but that's all they are- theories; we could find no indications of what would cause a parsley hawthorn to fail to bloom. 

Our first idea was sun exposure. The page on this plant in our Native Plant Database says it requires part shade, which we consider to be 2 to 6 hours of sun a day. It's a known fact that any flowering plant flowers better with more sunshine. Other websites said the tree grew well in sun (6 or more hours of sun a day) or part shade. In the shade of tall pines, it may not be getting enough sun, although we are surprised it doesn't at least try to put on a few blooms, because without blooms, it has no seed, and every plant wants to recreate itself.

Second thought, soil moisture. Several of the resources we consulted said it was a "swamp" plant, did well in very moist soil, and could even have its roots under water for a period without damage. 

Then, you mentioned fertilizer. Ordinarily, we don't recommend any fertilizer for native plants in their native locations. Parsley hawthorn appears to grow in or very near Madison County, and should have the kind of sandy, acidic soils it needs for best growth. If you are looking at fertilizer components, the N-P-K is nitrogen - phosphorus - potassium. The potassium in a fertilizer contributes to flowering and fruiting, including flower color and size. Since this tree blooms white March through May, it should not be fertilized now, but early next year, maybe in February, you might try some 10-10-20 or a similar ratio of one part nitrogen, one part phosphorus and 2 parts potassium to give the blooming a little boost. 

Finally, we come to age of the tree and when it was planted. If it was planted in the last year or so, particularly if it was planted in the summer, it may not yet have recovered from transplant shock. When a tree first goes into the ground, especially if it is planted in hot weather, the roots and indeed the whole tree system have to get organized and take first things first, like getting water to the leaves, so the leaves, through photosynthesis, can manufacture food for the whole plant. It takes a great deal of energy for a plant to bloom and set fruit, and it just may not have gotten to the point where it has that much energy. And that includes the question of age. Six feet tall is not very tall for a tree, and it may not yet have matured enough to bloom.

With the exception of sun exposure, all of these probabilities are easily addressed by a little patience, perhaps a little more water and a light application of fertilizer in the very early Spring. If it is not getting enough sun to bloom, you will have to decide if the lovely foliage is enough, or if you want to either transplant the tree (which will set it back still more) or trim up some of the trees that are shading it.

From our Native Plant Image Gallery:

Crataegus marshallii

Crataegus marshallii

Crataegus marshallii

Crataegus marshallii