How Do We Keep Those Orchids Blooming?

By Linda Peacock, Master Gardener, SCMG

Ah those lovely orchids, the strappy or grassy foliage is tropical and different compared to many houseplants but what we really want to see are those exotic blooms!  How do we do that?

Orchids actually thrive on very little care, however, what we do spend time doing can be important.

The most important thing we need to do for our orchid is find them the right spot in our homes.  Just like the plants in your garden, they need the right environment.  The right light, moisture, temperature and soil conditions.  Most of our homes are not great for tropical plants – they are just too dry.  Take a few minutes to research where your genus of orchid grows naturally to give you an idea of the right conditions.  Many grow in dappled shade in crooks of trees with no soil at all.  Which also means no medium to contain moisture for them.  So that means, first off all, we need to not drown or suffocate those roots.  Orchids are epiphytes – air plants – they must have air around their roots and have free drainage.

Typical orchid mixes do not include potting soil which would keep their roots too moist and cause them to rot.  These mixes include bark, coconut fibre, sphagnum moss, charcoal, eggshells, perlite or clay pebbles.  A few types such as Paphiopedilum and Ludisia are terrestrial and need soil, however, the majority of commonly sold orchids are not.

Healthy roots are plump, tuberous and white.  They have bright green tips if they are growing or no tips if they are resting.

They rarely need repotting, they love to “climb” out of the pot looking for more air – it does not mean they have outgrown the pot they are in.

The times you will need to repot your orchid are when the potting medium has broken down and needs replacing or when it is actually falling out of the pot.  When you do repot try to reposition it back in where it was comfortable, if it has snuggled up against the side of a pot, put it close to the new edge and leave some of the roots that are shooting upward out in the air. The best time to repot is when there is fresh rooting activity as shown above.  Soak your potting medium completely before you repot.

So now that we know it is comfortable in its little space where do we place it and how do we water and care for it?

They are happiest in bright, filtered light. Light can change many things for an orchid.  Direct sun will burn leaves quickly.  Yellow or reddish leaves mean too much light, deep dark green leaves mean not enough light.  Not enough sun means no blooms.  At my house they are the happiest in a west-facing window that is slightly shaded by a birch tree in the summer. They are happiest at about 22°C during the day and 16°C at night if that helps. I take mine out to a covered porch in the summer (north-facing) they love the light there but can dry out easier.  Their leaves turn a bit reddish as they adjust to more light but that goes away.  Generally, they just do not like it outside and the stress can be hard on them.

The biggest orchid killer is too much moisture.  Once every two weeks I take the whole pot and run water from the tap through it and let it sit in the sink until they drip dry.  They need to dry out quickly. I have well water; I would not use water-softener or treated water.  I do this once a week if it is flowering.  About once a month I use the bathtub and do them all. I let the shower water run through them then leave the shower curtain closed for a while to keep the humidity in while they drip dry.  Humidity is the hardest thing to control indoors so they often need a boost.  They need humidity but don’t like it hot and stuffy since they also need ventilation. I have placed them in trays of water propped up on stones (to keep them out of the water but enabling the moisture to evaporate around them).  It looks quite nice if you have the room for that.  If the leaves are dull or have wrinkles, they are dehydrated. I have tried placing them in the bathroom but there is not enough light in mine, at my house they do better above the kitchen sink (in a north-facing window with no shade).

I have found that all orchids do better with too little fertilizer as opposed to too much. Many resources suggest fertilizing when lush green leaves are growing or when flowering.  To me that is what we want to see all the time, so I dilute fertilizer by about ¼ and apply it every other watering.  I simply run the water through it first, then run the fertilizer through it next and let it drip dry.  It is cheapest to use a good water-soluble balanced fertilizer, if you are growing strictly in bark you could use a 3:1:1 ratio.

After all that your orchid is blooming – now what?  Out of the most common orchids the Phalaenopsis is the only one that will rebloom from an old flower spike.  Using a sharp knife cut it off between the scar left by the first (lowest) flower and the last (top) node on the spike.  The lower node should initiate a new spike within 8-12 weeks.  For any other orchid type, just cut the old flower spike off at the base.

Phalaenopsis, dendrobiums, and cattleyas will produce keikis that can be removed and potted to make new plants.  Let them grow on the host plant until the stems have hardened and the roots are at least 2.5 cm long.

 

That does seem like a lot of information that you need to remember so let’s sum it up and make it simple:

  • Don’t overwater or overfertilize
  • Give them lots of indirect light but not too much heat
  • Try to give them some humidity
  • They have few problems/pests
  • Enjoy them

 

 

 

 

 

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