When to Deflask

Paphiopedilum Final Replate

It is best to remove the flasklings from flask for compotting while they are in active growth. Ideally they will be nearly filling the flask, showing no yellowing of the leaves or browning of the leaf tips, and have active roots with white tips. Overgrown flasklings will do fine with care, but will be a little slower to establish themselves. The same is also true of smaller seedlings. If you can take them out while they are growing strongly, they will continue to grow with almost no setback while establishing in their new environment.

Obviously we cannot always take out the flasklings at the perfect time. They may be a little overgrown before you get them, or it may be a flask that jumbled in transit, or one that contaminated before you received it, or demands on your time may keep you from taking it out at peak. The flasklings should still do fine, they may just take a little more time to adapt and get growing again. Contaminated flasks should be taken out immediately if they are contaminated with mold (whitish, fuzzy appearance and generally covering the roots), or with a bacteria (slimey appearance covering the agar) that spreads quickly across the surface. Under these conditions the flasklings will almost certainly progress no further, and may actually be killed very quickly. Once in a while you can get lucky and the contamination will be by a bacteria that can only grow where there is excess moisture on the surface, usually along the walls of the flask. In this case, you can usually let the flask grow on, but watch it carefully.

Types of Flasks

Various Flasking Vessels

We use the Zuma square polycarbonate flasks for final replate. The other type of flask used most commonly by professional growers is the 500 ml erlenmeyer flask. You may also encounter milk bottles, French Squares (similar to milk bottles but less rounded corners and wider mouths), canning jars, magenta vessels (square polycarbonate vessels with a slide top), Phytacons (round plastic containers with a snap lid), and baby food jars. We have found the latter three to be very unsuitable for growing Paphs, and would recommend that you be careful to scrutinize the quality of seedlings in them before buying flasklings in them. Milk bottles, French Squares, and canning jars allow for a good growing plant, but are difficult to ship intact. The Zuma flask has the advantages of allowing a significantly larger grower area (compared to the other best choice, the erlenmeyer) while taking up the same space, allowing light in from the top, and being easy to deflask from without destroying the flask.

Getting the Flasklings Out

"Breaking" the agar in Zuma Flask

With the Zuma flasks you unscrew and remove the lid, then slam the side of the flask against your open palm, turn the flask on its side (not the top) 90 degrees, slam again, repeating this on all sides until you see the agar matrix start to collapse. Then it is simply a matter of sliding the seedlings out of the wide opening sideways.

Breaking the Flask With a Drift

If you are dealing with a glass container with a narrow opening (milk bottle or erlenmeyer), we suggest you resist the temptation to try to ease the flasklings out through the narrow opening, which will almost always cause damage, even if it isn't immediately apparent, and instead break the bottle. However, contrary to the common advice to wrap in newspaper and hit with a hammer, which can embed minute slivers of glass into the agar, which can then be embedded into you when you wash off the agar, we suggest a different method originally given to us by Terry Glancy. You need a "drift", which is sort of like a large metal rod or punch. You can make one out of a large bolt if you can't find one, but you should be able to get one, or something similar at a hardware store. The drift needs to be longer than the flask is tall. Wrap the flask in newspaper several layers thick, keeping the opening clear. Carefully push the drift down through the root and agar mass near the center of the flask until it contacts the glass, and give the drift a tap with a hammer. This will gently break the glass out, with little splintering, and is much safer for you and the plants.

Washing and Soaking

Gently Wash Off Agar

We gently shake any loose agar off the plant roots, or pry off more stubborn agar with a single chopstick, and then wash the rest off with a stream of warm water. Different plant types have different root types, ranging from the very wiry roots of some of the multiflorals which come free of the agar and each other very easily, to the fleshy, hairy brittle roots of brachys which cling to the agar and each other tenaciously. If the roots are seriously intertwined we do not go to any lengths to separate them. It is surprisingly easy to end up with leaf tops in one hand and the few, tiny roots in another. They will be easier to separate after they are ready to come out of compot, so at this stage we just take them apart enough to fit them into a compot.

Different Root Types

It is probably not necessary to use a nutrient or fungicidal or disinfectant soak at this time if the seedlings came from a uncontaminated flask and are in good shape. However a lot of people report good results using a combination of items. We use a dip that contains a very weak phosphorus fertilizer and Gamborg's plant vitamin mix. Others use Superthrive and others also use Physan. If you use Physan (or Consan or RD 20), use it very weakly, or you run the risk of burning the tender flasklings, which have very little cuticle at this point. It probably makes more sense to wait a few days and spray the compot with the disinfectant, rather than soak in it at deflasking. At any rate, if you have a method that works well for you, stick with it. Sometimes it is suggested to dip the plants in an antitranspirant such as Cloud Cover or Wilt Pruf. We have experimented with these and have decided not to use these products. We found one providing no significant benefit and the other deleterious in some cases. If you do try them, be very careful not to exceed the proper concentration.

At this stage we discard any runted, damaged, deformed or proliferated flasklings, it does not pay to waste space on them.

Containers and Medium

Planting Flasklings in a Clump in a 2.5" Pot

Again, there are a vast number of possibilities for containers into which you can pot your seedlings. The key is to match the pot, and your growing mix, to your conditions, particularly with regards to temperature, humidity and air movement, which will affect the speed at which your compot dries out. We want the compots to need watering about every three to four days, and under our conditions this means fairly small containers. We have settled for now on two techniques, clumping the seedlings into 2.5 inch (deep) rose pots or, for the more succulent rooted brachys and parvis, compotting into the 5 x 5 inch mesh bottom compots. We are in the process of installing a bottom heat system for the compots, at which time we will probably be able to go completely to the 5x5 compots, or possibly even to 1020 flats.

The medium you use should be able to anchor the plants securely, preventing wobbling, and yet allow for free draining of the irrigation water, and should be able to somewhat dry out within three to four days. We currently use a mixture of approximately six parts soaked fine fir bark to two parts extra course horticultural perlite (this is the small perlite, not to be confused with spongerock) to one part of New Zealand sphagnum moss chopped (cut with scissors) into half inch lengths. This is an easy mix to use, and to adjust to different conditions.

Planting

Planting the 5x5 Compot

First, resist the temptation to segregate and pot out the bigger seedlings individually. Seedlings fresh from flask do not yet have the tough cuticle that an adult plant has developed. All seedlings will appreciate the nurturing microclimate provided by the compot approach.

When using the clumping method with the 2.5 inch deep pots, we find that seedlings from one flask will usually comfortably fit into three to four such pots (our flasks are now all plated with 36 or more seedlings). A group of the plants of approximately equal size is gathered together and aligned as much as possible, so that the root-plant junction is at the same height for all. A little mix is put in the bottom of the pot, and the plant clump is held in the center while mix is placed and packed evenly around them. The mix is packed in quite firmly, and a cross tag is placed in the pot. When you are clumping like this, you will need to plan on recompotting again in about four to six months to allow the seedlings more room to grow.

Finishing the 5x5 Compot

When potting out into the 5 x 5 inch compots, a layer of medium is placed over the entire bottom. Then the compot is propped up on its side at a 30 to 40 degree angle and a bank of medium placed inside the compot, along the lower edge. A row of plants is laid along this bank and sufficient potting mix is added to cover their roots, or nearly so, then another line of seedlings is added, and the process is repeated, until the compot is full. The compot is then allowed to lay flat, and the medium is carefully tamped along the edges and between the rows. The seedlings should be able to stay in this compot for six months to a year or so.

Post Planting Care

Paphiopedilum 2.5 inch Compot After 6 Months

It is very important to keep the freshly deflasked seedlings in very subdued light initially, probably no more than 800 - 900 foot candles. They were grown in flask under similar lighting conditions, and the transition to higher levels should be made gradually over several weeks, or you will risk stunting or even killing them. We place them under our benches initially. Growing them under a two tube fluorescent fixture is another good possibility.

Compots are fed weakly but steadily; we use RO water for irrigation and Peter's Excel Cal-Mag fertilizer at a conductivity of 350 - 400 microsiemens and pH of 6.0 - 6.5. They are allowed to approach dryness but not completely dry out. It cannot be stated enough that the addition of any fertilizer to your irrigation water will change the pH, and very low or very high pH levels will render many nutrients completely unavailable to your seedlings.

Paphiopedilum delenatii Compot After Two Months

Within seven to ten days post planting we apply a spray of a fungicide directed at Pythium and Phytophthora species. This spray is again repeated in about three months. Under ideal conditions these sprays would not be necessary.

It is best to try to keep the seedlings quite warm through this early period, probably 75 to 78 degrees Fahrenheit would be ideal. Bottom heat is preferable.