Cymbidiums & Fertilizer
 

I have always known that Cymbdiums were greedy plants. Let me share some recent experiences:

In late 2015 I decided to expand my collection. I purchased a number of plants from Casa de las Orchideas in November.
A. BS seedlings in 6" pots (supplied out of pot).
B. 3" seedlings, supplied in pot in a fibrous mix. These went into 5.1/2" pots in my mix (see below).

Following the two NJ shows in Jan & Feb 2016, I noticed that none of the other vendors offered Cymbidiums for sale, so I ordered an additional lot of mature plants, intended for resale.

I used the same mix for all:

• Abt 3 parts chunky peat
• Abt 2 parts composted manure (= 1:1:1)
• 1 part medium bark
• 1 part perlite

Plants went outside into full sun in May, and we watered them twice a week throughout the summer.

• We added a handful of NutraCote into each pot (1 Tsp in 5.5" pots, and 2-3 Tsps in mature plant pots).
• We watered with fertilizer (Peters 20:20:20) every 2 weeks.

The plants were brought inside in late October, as we had early frost by the greenhouse (in Califon, NJ).

With this treatment (and feeding schedule):
90% of the mature plants are in spike.
20-25% of seedlings are spiking too, a year ahead of the anticipated schedule.

A couple of photos of the plants in the summer location to show that they have no problems handling full sun (a few plants got some minor burns where the leaf curves over). And, as you can see in the second photo, my reedstem Epis go into full sun too.

You have probably heard the saying, "if you ask 10 different growers, you will get 12 different answers." Few people can grow Cyms successfully in that heavy a mix with the high water retention capability, but it apparently worked for you. The real test will be if the roots continue to thrive over the next 3 years in that mix. If they do, then - "if it ain't broke, don't fix it'.

This is roughly the mix used by Koch nurseries in Denmark. They had approx. 400,000 sqft with Cymbidium for cut flower production (grown in laundry baskets and repotted every 4-5 years).

I grow mine in pots only just big enough for the plant, so I typically have to repot every 3 years.

For me, cymbidiums have always done best in LECA, either with heavy watering in traditional pots, or in semi-hydroponics. Airy, but constantly moist.

Many moons ago, I imported about 500 "Chinese" cymbidiums a month from Taiwan, and learned that they had been grown in a mix of pumice and tree fern (and fed with diluted, spoiled milk).

I've had incredible results using horse manure, since posting this link on OB a few years ago

Nic van den Bosch's Home Page

The only genus I don't use it on are phals as I grow them in sphagnum moss only. Paphs, phrags, catasetinae, cymbidiums, dens, habenaria, cats - all love it. About a third of the pot is composted manure with normal bark mix on top.

Horse manure is much prized by rose growers, and I can certainly see how it can be used for terrestrial orchids (I would probably want to let it 'cook' for a couple of seasons rather than use it fresh). I am somewhat surprised to see it used for Cattleyas, but it is worth trying. I am in 'horse country', so I will have to hook up with one of the local stables.

It isn't just what you pot in but the climate in which you grow. Cymbidiums will grow in just about anything if you use your water accordingly. Hot/humid parts of the country will do better in a fast draining mix. Hot/dry a mix that retains water is preferred. Even plants under ideal greenhouse conditions will perform differently under the same mix as those grown outside in natural conditions.

Sp far, you have five responses and five different suggestions for mix. The bottom line is to use what works best for you. And if you do decide to change or add ingredients, use it on only a few plants.

I am very leery of using horse manure in any form, as it is just too hot unless thoroughly aged and heavily diluted. Never use fresh, that is for certain. There are so many high quality fertilizers on the market, that using manure, although cheap, may not be the answer in the long run.

I have only one Cymbidium right now (my other one was murdered by squirrels that ate its pseudobulbs). The survivor was repotted in a mix of medium bark, charcoal, eggshell (maybe 5%) and municipal compost 10-15% (the compost is made of yard waste and wastewater treatment solids). The plant is growing like crazy and is spiking but not blooming yet.

I use only bark and they bloom every years. Main thing for them to bloom successfuly is temp drop.
At least according my experience... I don't pay much attention to them, sometimes even forget to water them, and they grow like crazy.

I agree about temperature. For mine a cool down seems essential to spike and not blast. Mine stays outdoors unless temperatures are forecast in the lower 30s F.