RE: Pruning Lacecap Hydranges? When. Do They Grow On Previous Years Stem ? What Type Of Fertilizer To Use?

Question

I had lush green leaves this year but not one flower. I did prune last fall and fertilize with osamate early spring.

Answer 1

Depends on what type of hydrangea species this is. Hydrangea arborescens (also knows as Annabelle-like Hydrangeas or Smooth Hydrangeas) can be pruned now or better in late winter so new growth does not get zapped. But hydrangea macrophyllas (Big Leaf Hydrangea, French Hydrangea, Hortensia), Hydrangea Serrata (aka Mountain Hydrangea), Hydrangea Anoala subsp. Petiolaris (aka, Climbing Hydrangea) and Hydrangea Aspera (aka Rough Leaf Hydrangea) currently all have developed invisible flower buds at the ends of the stems/branches and should never be prune from mid/late until after they finish blooming. You can deadhead spent blooms at any time (cut the peduncle string that connects the bloom to the stem) and prune dead wood from prior years by the end of May. The last set of species mentioned above all bloom on old wood but some varieties bloom on old and new wood (both). Hydrangea arborescens only blooms on new wood and starts to develop/open blooms from around mid spring on forward, blooming in late spring or in the summer. You can use a general purpose, slow release, chemical fertilizer with a NPK Ratio of 10-10-10 per label directions in spring 2022 only (I am assuming no soil nutrient deficiencies and that the plant is well established). Or you can use 1 cup of cottonseed meal, organic compost or composted manure in spring only. It actually depends on other factors like how old and tall the plant is, soil type, any soil nutrient deficiencies, etc but a recently purchased hydrangea (the size of one one found at Lowes. HD or local plant nursery) may be fine with 1 cup of those three items… less when it is a cutting or smaller plant. Fertilize after all danger of frost has passed (ave. date of last frost is 1st week in May).