Repotting using lava rocks?

[sharon lynn]

Hi ..I was just watching a video and it was repotting Phal’s in lava rock ..good idea? Also I have a small Milt.Bert Field as well as small Onc Heaven scent...neither one are stable in their pots & I've tried stabilizing them both with no luck..They are both in bark medium..I’m wondering if maybe they would do better in lava rock? 🤔🤔They are both in clear plastic 4” pots that I’d keep them in .. as always any advice is appreciated :😄

[SaraJean]

Hi Shanon!

Choosing the proper media is based on a combination of: 50% your individual conditions and culture, and 50% what type of orchid it is. Or maybe it’s a 60/40 split, or 70/30, or whatever
It’s hard to say if lava rock will work for you since I don’t know what your conditions are like. If you have decent humidity or you water frequently, yes it can be a great media choice. But there are draw backs to it like anything else. I live in a VERY rainy, humid climate (all of my orchids are grown outdoors 9-12 months out of the year) and I have a heavy hand when it comes to watering. Lava rock can work great for many of my orchids since it provides excellent drainage and lots of air space around the roots. I have had not rot issues in lava rock even though it may rain non stop for days and days on end. However, on non rainy days, it doesn’t retain enough water for some of my moisture lovers and daily water with the hose isn’t enough for those types. I now keep those in bark. Lava rock can also hold on to salts from fertilizer. Salt build up can potentially be a real problem over time if there is not enough pure water flushing out the media. If you have never used lava rock before and want to try it with a Phal, go for it and observe it for a while first to see how it works for you rather than changing all of your orchids to it. I can say that it will most likely need to be watered more frequently than your current media, but I can’t say how often that would be. You can also add lava rock to bark as an amendment that will improve drainage.

Personally, I would hesitate putting something like a Oncidium or Milt in lava rock, I would worry about it being too chunky and dry for the root zone of these fine rooted types. If you are having stability problems with those (when was the last time you repotted?), try staking it with a bamboo skewer and some twist ties. Sometimes it can take many, many months for an orchid to get itself stable in a new pot. That’s assuming these two orchids have good root systems to begin with. Lava rock won’t necessarily help roots grow. It is more about the growing cycle of the orchid (i.e. is it “time” for that growth to make roots?), and also humidity and/or watering practices (roots tips tend to stop growing when they get too dry).

[SouthPark]

Totally agree with sarajean on the - depends on conditions. This includes local conditions (humidity, air circulation conditions, temperature etc.) and watering schedule.

In my part of the world - North East Queensland - Australia, I'm growing cattleya type orchids, oncidium, vanda, angraecum, paph, phrag, encyclia, psycopsis, dendrobium --- all in lava rock (locally sourced as quincan gravel - pronounced as 'kwing-kun' gravel). The conditions are just fine for growing in lava rock, and the other factor will mainly be watering schedule.

As for sharon's situation about stabilising the plant, like a phal --- there are various average diameter sizes of lava rock that can be purchased - if available that is. Eg 5 mm average diameter, 10 mm average diameter, 15 mm, 20 mm etc.

For small plants, baby plants etc, maybe relatively small average diameter is good, like 5 mm diameter. Big plants could do fine with 10 mm to 20 mm diameter. But then, they may do well with 5 mm diameter too - making sure watering schedule and air-circulation are factored in.

I've never grown phals before though. But I do know of somebody that successfully grows phals in lava rock in this part of the world.

I use black-coloured plastic pots for all my orchids. With nice drainage holes at the bottom - to make sure I get good drainage (and air circulation). I use non-see-through - just to avoid light getting through the pot, and growing algae etc, which could then die/decay, and create issues in the pot. Now, I don't know for sure whether it could really cause issues if I used clear pots. So my use of non-see-through pots is based on own assumptions right now.

[sharon lynn]

SaraJean,& South Park I live in Golden,BC Canada,heading into winter 🥶 all my plants are inside. I would say humidity is low ,propane furnace makes house dry.l do have a lot of large windows facing all directions so that’s a big help . I’m just starting to get some new varieties of orchids,up till now have only had Phal’s....I will try your idea of using bamboo stakes in my Milt.& Onc. They are both new plants from a nursery,both are babies.. I think I overwatered the Milt because 3 of the leaves turned yellow & died ,that’s why I was thinking of using lava rock..also thought it might help stability..they are both in 4” clear plastic pots . I have never taken the milt or Onc out of pot or medium they came in (bark) I have good luck with my Phal’s so decided to get brave & try other types of orchids 😀

[sharon lynn]

http://www.orchidboard.com/community...1&d=1572647386
Hope I’ve done this right. It’s supposed to be a picture of my Phal that’s blooming now

[SouthPark]

Originally Posted by sharon lynn

so decided to get brave & try other types of orchids 😀

This is quite good, and the start of gaining experience in growing other types of orchids and trying other types of media, and learning what can be done, or what needs to be done to grow particular kinds of orchids under particular conditions.

[DirtyCoconuts]

You are doing something right as that phal is popping.

I use a bucket system where I have four big buckets. One with bark chunks, one with lava rocks, one with charcoal (chunk wood, not briquettes), and one with coconut coir and the dried shield leaves of old stag horn ferns. Depending on the orchid’s needs and location, I mix accordingly.

I subscribe to the school of thought where I water a lot and want super fast drainage and great air flow. For the damp loving orchids I add more coir and some sphag as appropriate

I refer to about 45-70 of my orchids as “plant experiments”.....let’s see how this works out lol

[sharon lynn]

This is one of my Phal’s that bloomed this summer (2019) had pretty yellow flowershttp://www.orchidboard.com/community/attachment.php?attachmentid=140420&d=1572670568
Sorry,I don’t know how to turn it around 🤔. I’ll post some of my others that bloomed ..I’ve had most of these since 2007.. they are all steady bloomers for me 😁 sorry ..I should have said I started getting them in 2007 & have got them on a regular basis since ..& most of them are repeat bloomers ..

[sharon lynn]

Here’s some more pictures I do love it when I have lots of different flowers blooming at the same time ..I also have some that bloom after the others as well ..I manage to have at least one blooming most of the year 😁http://www.orchidboard.com/community...1&d=1572671121
Hope you all enjoy the pics!

[DirtyCoconuts]

A friend of mine and I had a sort of joke about having a constant bloom and who could accomplish at least one flower all year long in the fewest plants.

After a while I stopped caring and realized that sheer numbers increased my odds. He has year round flowers with like 26 plants, if memory serves.....I have over a hundred and often have nothing in bloom lol


I like roots anyways