Orchid fertilizer: how to feed a moth orchid

Orchid fertilizer: how to feed a moth orchid

1. 01

   How often to fertilize an orchid

   The advice agrees as long as the dose stays low. The American Orchid Society feeds weekly at half strength. The Missouri Botanical Garden feeds every week, or three weeks out of four, after watering, also at half strength. Iowa State feeds often at quarter strength or less.

   The University of Maryland feeds growing and flowering plants about every third or fourth watering, following the label. The RHS says to feed lightly but regularly.

2. 02

   Which orchid fertilizer to use

   An orchid fertilizer, says the RHS. The American Orchid Society and the Missouri Botanical Garden name a balanced fertilizer such as 20-20-20. Iowa State recommends a water-soluble fertilizer without urea.

   Never mix it stronger than the label says. The sources stay below it.

3. 03

   How to feed it

   Mix the fertilizer into the water. If the bark is very dry, water with plain water first, as Iowa State advises.

   Fertilizers are salts that build up in the bark. Flush the pot thoroughly with plain water once a month, as the American Orchid Society, the Missouri Botanical Garden and Iowa State advise. The RHS uses plain water every fourth watering.

4. 04

   Fertilizing an orchid in winter

   In cool, low-light months the orchid grows more slowly. The RHS feeds sparingly or not at all, the University of Maryland skips feeding and Iowa State feeds only in spring and summer. The Missouri Botanical Garden feeds at quarter strength in winter.

   If your orchid sits somewhere warm and bright and keeps growing, a weak dose is enough. If it sits somewhere cool, skip the fertilizer.

5. 05

   While it blooms and after repotting

   Keep feeding weakly while it blooms and while you wait for new flowers, as the American Orchid Society advises. The University of Maryland feeds flowering plants too.

   After repotting, wait several weeks before feeding, as UF/IFAS advises.

6. 06

   Too much fertilizer

   The RHS warns that overfeeding can do more harm than good. UF/IFAS says too much fertilizer can hold back flowering, and the University of Maryland says it pushes leaves at the expense of flowers.

   The RHS also warns that feeding at every watering builds up harmful salts. Weak and regular works better.

Common questions