Do you fertilize blooming plants?

[Marci in SoFL]

This question always nags at me. Should one fertilize blooming plants?

[raybark]

I will start by saying that I feed everything at every watering, using a dilute fertilizer solution. It seems to me that in nature, nutrition is a more-or-less constant, whether it is in the form of detritus, or the nutrient-laden rain cascading through the forest canopy, so i try to follow that example to some extent.

That said, growing and carrying an inflorescence is a mighty resource-consuming activity for a plant, and all the while, its other metabolic processes are carrying on, so keeping up the nutrition seems advisable.

[Marci in SoFL]

Ray, I've come to think of you as the Mr. Spock of Orchidom because you are always so logical! Thank you!

[Ricardo in PR]

Unless the plant is producing new growth, either as pseudobulbs or as roots, I don't fertilize. I can't say I have noted any loss of vigor of my plants because they don't get fertilizer out of the growing season.

[raybark]

Marci: Thanks, but I suggest you do your own evaluation before "buying" my logic. I'm in no way as infallible as he!

Two comments, Ricardo:

1) Plants do store nutrients for future use, so NOT feeding them regularly is probably not a heinous act.

2) How do you know your plants wouldn't be better if you DID feed more often? (I'm not saying they would be, but how do you know if you don't try?)

If I can throw out another analogy, think about our own diet. We don't only feed people while they are growing children, as there are metabolic processes that need to be supported. AND...any nutritionist will tell you that relatively frequent, small meals are actually better for you than the approach of binge eating, followed by periods of starvation.

[Marci in SoFL]

Ray and Ricardo, thank you for the interesting input. Definitely 'food' for thought.

[Ricardo in PR]

In response to your comment #2, I freely admit that perhaps some particular plants and genera could do better, the problem is, what metric would I use to judge this on a plant that is just sitting there unchanging producing neither roots nor leaves?

I have roughly 35 genera of orchids, this means there isn't a single schedule of fertilizer application on my collection. On one extreme sit the Arachnis and Papilionanthes which get fertilizer every time they are watered. On the other extreme are the Calanthes, Catasetum and Habenarias which sometimes don't get fertilizer or water for months on end.

Also I take into consideration the seasonality of the plants as in some Dendrobium fertilizing when they are in their rest period can make them produce keikis instead of flowers.

I have seen people produce outstanding results with continual fertilizing and watering on particular hybrids that lack seasonality and grow continuously but that is not the case with most of my plants.

[Kentucky]

Basically I agree with Ray, but Ricardo makes a good point about plants that go dormant. Even watering some plants in their dormant period can be deadly. Try watering the bulblets on Habinaria during winter.

BUT to return to the original question...should plants be fertilized while flowering? I believe Ray is correct...blooming takes energy and that needs to be replaced. Since flowering is the first stage of a sexual phase of growth, it makes sense that a plant would not flower immediately before going dormant. Why produce a a flower and go dormant with a seed pod in place? Seems perfectly rational to me that fertilizing during flowering might very well be the most important time because the plant is preparing for producing seed ...even if that never happens.

[raybark]

Originally Posted by Kentucky

... Ricardo makes a good point about plants that go dormant. Even watering some plants in their dormant period can be deadly. Try watering the bulblets on Habinaria during winter.

Absolutely correct! But I am an "equal opportunity abuser" of orchids. If it doesn't like my constant feeding, it will either never bloom or die. No special care for anything.

[Ricardo in PR]

A good portion of my plant collection is composed of species. This means that I have to take into account their seasonal growth/rest cycle when watering and fertilizing. I don't find this an onerous task as I don't have a very large collection. For example, when the anosmum, cucullatum, parishii, nobile, primulinum group of Dendrobium start losing their leaves I stop all watering and fertilizing. For the next three months these species need very little care at all. If I kept watering and fertilizing them the result would be a lot of keikis and few flowers.

With regards to fertilizing during blooming, I read somewhere probably in the Orchids magazine that fertilizing during blooming could potentially shorten the lives of the flowers because it affected the osmotic balance of the plant and drew water away from the flowers. Unfortunately I can't recall where I read it. Perhaps one day, when we have a searchable database of all the AOS articles I will be able to find it.