Growing Masdevallia by Keith Kent – 8th Dec 2010
This article is purely what I do and what I think Masdevallias like, I am no professional so don’t profess to be the authority on the subject.
All I would say is take what you can from this and don’t just change everything you are doing on the word of someone else, saying this if you are not doing to well with your Masdevallias then you will most likely change more, than someone who is growing them relatively well.
I am having really good success with Masdevallias even though I don’t win them all, I wouldn’t blame my culture for many loses but the purchase of bare root plants that just didn’t make it in the end. This though was understandable as I have had a fair few of them, they need more nurturing than plants that are acclimatized and already have active roots. What is the saying ‘you cannot win them all’ and we all will have orchid deaths unfortunately.
Good roots, what we all aspire to
Not good, but will recover
Any bare rooted plants have taken me up to 3 years to get to a good size so you need to be more patient if you go down this route. It is often a cheaper route but is not an instant result, so for most is not a option. Masdevallias do lose roots whether it be by nature, rot, division etc but they do recover well so don’t be too disheartened if this is what you are confronted with. The picture of the good roots is of an established plant that is ready for repotting so I would say is unrealistic to expect this for all your plants that are at different stages.
I grow in a fairly large greenhouse; (28 x 13) well for Masdevallias that is anyway, that has the potential to house a full collection of Masdevallia species; which is the aim.
When I built the greenhouse the aim was to build it with the minimum heat loss possible that I good fit in to the budget, so I chose 25 mm triple wall polycarbonate sheets for the roof, ends, sides and a concrete block wall up to staging height.
My philosophy with this is no matter what my electric bill is I know pretty much that I can do no more to save money. This isn’t making it any easier though as we are experiencing the coldest weather we have had in years, so as I write this I know that the temperature is going to drop down into double figures and put a stress on the wallet. We had a low of -14 last night(7th Dec 2010) and it felt like the heaters never stopped!
I had a 10 x 8 aluminium greenhouse with 4mm glazing that lost heat almost quicker that I was pumping it in so it was always in my mind what I can do to reduce the loss. The answer is not a lot, the options are limited so have this in mind at the very start if you are planning a greenhouse project. You can use bubble insulation to reduce heat loss but I found it got in the way, the glass is then difficult to maintain and clean.
You will find the temperature range guide helpful to see the difference in temperatures from other orchids and a guide when purchasing plants from me, as I will tell you what range the species is in.
I have split my greenhouse down the middle and have two temperature zones of 10c minimum and 5c minimum, I don’t artificially raise the daytime temperature and find that solar gain is enough for good growth and flowers. I do have to be wary of overzealous watering and spraying and start to dry the greenhouse out in autumn so stop damping down the floors etc. Condensation is a problem i have yet to resolve but plan to install a large extractor fan.
In summer, high temperatures will be a problem if you don’t manage them properly and I like to have a maximum of 29c/85f if possible.
But this can be a challenge on the hottest days so the temperature may nudge to 32c/90f or slightly above for a short time, I have found the plants will be fine as long as the humidity is also at a acceptable level and they get good air flow. I open up the greenhouse doors and windows that remain like this from the last frosts until the first frosts.
Leaf tips may become brown or become spotted which is stress related, so watch the summer high temperatures.
Masdevallia like high humidity ideally around 70%, achieving this optimum is a challenge as it is for all orchids.
I have a hydrofogger to keep the humidity above 50% minimum in summer and this is turned off when the natural humidity levels stay more constant in autumn.
Damping down the floors in summer and spraying the plants helps with keeping humidity levels acceptable.
I would like a maximum humidity high of 80% in winter but I haven’t managed this as of yet as the humidity goes above this especially at night. This is where I would like an extractor fan, which I think would help this humidity high with air exchange and reduce the temperature in summer. Humidity gauges are useful only to give an idea of high or low and shouldn’t be taken as a accurate reading, I have learnt what I need to do to get the lowest maximum summer temperature with the highest humidity possible so they are only taken as a guide.
Most Masdevallia in nature grow in shady areas, approximately 1200 foot candles and some are found in higher light areas around 3500 foot candles.
A general guide is the plants with thinner leaves prefer shadier conditions, than those with thicker leaves that can take lighter conditions. In no circumstances should Masdevallias be exposed to full sun; the light should be diffused.
I have found that I have to add shading until the acceptable summer high temperature is under control, so obviously temperature and light go together.
Masdevallias when under severe stress due to heat and light can drop their leaves. This can be a shock for the grower too. They may recover if given a shady, cooler spot. This has only happened to me once, when I purchased one of my first Masdevallias and the greenhouse got too hot and the plant too dry.
Air is very important to Masdevallia culture as it is for any orchids; I have circulation fans running 24/7 and like to see the leaves gently moving in the air flow.
I open up the greenhouse when I can so there is regular exchange of air, even on nice sunny winter days I may open the door for a short period. This all helps to prevent cold spots, fungal growth, bacterial rots and keeps the air moving so the plants don’t remain wet for long when they have been watered.
Watering & Feeding
I cannot stress enough how important watering and feeding is, I am not in the camp of orchids don’t need feeding, or feed once a month.
But prefer to feed little and often so I feed at every watering all through the year, and choose to use reverse osmosis as my water source. Reverse osmosis water is clean and pure but inert so you have to have the correct feed to suit; I use Akerne orchids rain/ro mix. I use RO as I got tired of running out of rainwater in summer and struggled to keep the rainwater clean, also I know exactly what my plants are getting.
Tap water can be used but I wouldn’t recommend it, if you do use it then let it stand in the same area as the orchids to get the ambient temperature the same as the room.
Be mindful if you choose rainwater, make sure that the surface it is collected from is clean and doesn’t change the PH to an unacceptable range.
When I have mixed my feed to water I test the ph and aim for 6.0 – 6.2 and alter within this range with hydroponics ph up and down where required.
RO has a neutral 7.0 ph and when the feed is added the ph will normally crash well below ph 6.0, you may think this isn’t much, but in terms of ph levels is massive.
Rainwater is normally acidic, mostly too acidic when feed is added depending on the feed. When I first started growing orchids i used a tomato feed with rainwater and never measured feed strength or ph. When I had my water tested by a friend it was found that my ph was around 5.0, which can lock out certain elements of the feed.
Hence the importance of monitoring the ph levels before you give the mixture to your plants. I also measure feed strength and am pretty much at Akernes recommended level now for all orchids at 1/2 gram per litre, this equates for meand my EC pen to be about 550-600 microsiemens.
If this seems too daunting to get into then I would recommend feeding at quarter strength at every watering and use a feed that includes calcium and magnesium, I wouldn’t under estimate the ph so would advise to always monitor. Electrical Conductivity and ph pens can be purchased for an affordable amount and are well worth the extra effort that becomes second nature before long.
How and when to water is often a frequent orchid question in the orchid world, and bluntly putting it is when the plant needs it!
This can be up to three times a week or more in summer and once a week or more in winter, every growers conditions and potting mix is different so this is something that needs to be learnt. Masdevallia like moisture at the roots as they don’t have pseudobulbs to store water but you have to be careful the potting mix doesn’t become soggy. I let mine slightly dry between watering and think they can handle the slightly drier more than I first thought so don’t over water.
In summer I love to spray and foliar feed my plants and would say I do this everyday, i don’t think the plants actually take much of this feed in but i am sure they benefit anyway.
Pests and Disease
Masdevallia are no different to any other orchid so will suffer an attack at some point from the usual common suspects; aphids, mealy bugs, scale, mites, thrips, slugs and snails. I have found prevention is better than cure so be vigilant and inspect your plants on a regular basis; clean the leaves with tepid water. This not only makes your leaves shine but will wipe away any pest you cannot see with the naked eye.
I use Provado Ultimate bug killer and use it to recommendations as a preventative instead of waiting for an attack to occur I also use slug pellets sparingly and periodically scatter these on the gravel as a preventative.
Disease can occur with fungus, bacterial rots and virus, I can say I haven’t had many problems with regards to this apart from when I may have watered too liberally thus rotting growths which seems to spread very quickly.
I always have cinnamon to hand and sprinkle over any infections or open cuts. I also use Physan 20 that is a fungicide and use it as a preventative about every 2 months.
Aphid Vine Weevil Mealybug
I won’t go into potting mixes too much as I find it is pretty much a personal choice and what works for you is usually good enough. The chosen mix needs to hold some moisture whilst holding air, I am having good results with coconut husk so all of my personnel collection are potted in husk. Masdevallia will do well in only sphagnum moss, or a bark mix comprising of fine bark, moss, perlite and change the ratio of the three to suit your conditions. So if your plants dry very quickly then add more moss for example. I got tired of sourcing bark and having a few materials for one mix so wanted to simplify, hence I now only use coconut husk. I did try sphagnum moss but it wasn’t right for me, I do however find it good for use with plants I sell.
For really good Masdevallia resources I would recommend the Masdevallia World CD by Sue Skittrell; which is for sale in my products section. Also I really like the book: Masdevallia Gems of the Orchid World.
Hopefully you have found something useful here that you can take into your own regime to grow your Masdevallias more successfully. Each of the areas I have covered could be covered in greater depth, but I feel this is adequate for most.
If you have any questions or feedback then don’t hesitate to contact us!