Bob/Lynn

I found your posting on bracy culture most interesting and am enjoying your Web site very much. Some questions on the brachy info:

(1) Your culture guide states that you feed at a rate of 600 microsiemens. What fertilizer do you use and can you tell me what the equivalent of 600 microsiemens in teaspoons per gallon would be? I am a small hobbyist grower. Also, how often -- monthly, twice a month, weekly every feeding?

(2) Same questions for calcium nitrate and magnesium sulfate -- can you suggest a rate in teaspoons per gallon and a frequency?

(3) Can you suggest a source for high intensity lights?

(4) I am using 48-inch VITA Power Twist tubes on the lower benches in my greenhouse. They are expensive: $13 and change per tube. The Ultralume 5000Ks you use are available in Atlanta for $8 and change per tube. Do you know if one tube is better than the other? Cheers Tom

(Note: Everyone's conditions are very different, and you must balance the various factors of your growing with each other. What is stated here is how we fertilize, and it may not work for everyone, but it is hoped that there may be aspects discussed that may be useful to you. We suggest that careful experimentation on small numbers of plants be carried out before anyone makes any major change in their growing conditions. Also, everyone does not have the same goals in growing, and may not be interested in trying to tease every last bit of potential out of their plants. I welcome feedback from anyone receiving this. Warning though, I may forward pertinent comments to the rest of the list recipients!) Hi Tom,

I am guessing that our rate of fertilizer in teaspoons per gallon is in the 1/2 to 3/4 per gallon rate, and is the same whether it is 20-20-20, 9-45-15, calcium nitrate or magnesium sulfate. I tend to fertilize towards the low end in the winter and towards the high end in warmer weather. We use low urea fertilizer, greenhouse grade calcium nitrate and Epsom salts for the magnesium sulfate. We use only RO water with less than 10ppm TDS, and fertilize with one of the above virtually every watering, using unfertilized RO water maybe only once every 3 to 4 weeks (all of this is for Paphs, Phrags are fertilized at a lower rate and flushed more frequently.)One of the waterings at least every two weeks will be the calcium sulfate and another the Epsom Salts. Except for a period in the early fall, when we apply the high phosphorus fertilizer for about 3 weeks in a row, we use the 20-20-20 about 3 times in a row and then the 9-45-15 once. The pH is monitored and adjusted if necessary to between 6.2 and 6.5. As you can see, for us not much is fixed in stone, the program is not precise. We think the keys are the use of RO water, maintaining proper pH, and feeding at a fairly high level. Before we switched to the RO water our well water had a TDS of about 150 ppm, not bad by most peoples standards. However, we noticed a huge improvement in our plants when we went to RO water. The charts for acceptable water quality frequently quoted (the ones that say 600 ppm is acceptable) were generated in 1949 for the irrigation of field crops in the midwest. Hydroponic growers have much more exacting standards, and it is essentially hydroponic growing that we do with our orchids. Having said that, I would add that using RO water makes it more critical to feed everything the plants need in the form of fertilizer, and the use of calcium nitrate and magnesium sulfate becomes more critical, and pH has to be monitored more carefully also, but the benefits are great. It is my personal belief that most growers would see an improvement even without RO water if they would feed Epsom Salts every three weeks or so instead of their regular fertilizer. A couple of our customers with large nurseries have also switched to an RO program, and have reported tremendous gains in plant quality and blooming.

As far as a source for HID lighting, I don't have a specific recommendation. We bought a hydroponic gardening magazine and checked out the ads, and ended up buying our lights from a nearby store selling hydroponic supplies and beer making kits! As a quick side note, although we are very pleased with the use of HID lights as a supplement to natural light, and for lengthening the day in the winter in the greenhouse, we were not totally pleased with either the Son-Agro High Pressure Sodium or Metal Halide HID as the only light source for Paphs. We are very pleased with the Phillips C50 ultralume fluorescent tubes you asked about, and would think they would work well for supplemental lighting on your lower benches. We use them as the exclusive light source for a large number of plants that still grow in our basement (can't talk Lynn into trusting the greenhouses for everything). The $8 price tag is a little high, is that a case price? We get them around $6 per tube.

Bob

> Thanks, Bob, for your excellent presentation on fertilizers. I have a couple of questions/comments.

My meter reads in ppm. Is MicroSiemens equivalent?

What kind of ppm di you find on calcium nitrate or epsom salts at the 1/2 t. rate? I've always thought of these as being quite "salty." I've not used Epsom salts in a long time (I'm also on RO) but have used Peters Cal Mag (and hope it has a similar positive effect). The problem I have with IT in RO water is a very low pH, which has to be adjusted. I'm curious about what your pH and ppm are on those.

I was talking to Herman Pigors (yes, another trip to the Chicago growers for the Hausermann's Open House--would have been cheaper to stay home, I think!), and he said he thought I should use some well water (mine is closer to 190 ppm) from time to time or mix it in my RO for paphs so that I would get more calcium! Haven't done it yet.

I have been using GE Chroma 50 light bulbs. Do you have any idea if they are similar to the Philips C50?

I've also been using the Wildcatt database for the first time this weekend, and have a few comments and questions about that. My first comment is that I'm trying to straighten out the spelling problems in my lists and tags. A few of them are mine, but many more came that way from the growers. One would think that growers that specialize in paphs could at least spell the species names correctly! I'm finding lots of hybrid names. What annoys me is finding that plants have been sold under the crosss name when the cross was registered 50-100 years ago! I have also found several "named" plants whose names do not appear in the list.

And then there are the taxonomic "difficulties." I am aware that RHS has chosen certain taxonomic "conventions" to make it possible to register hybrids. I know that these don't always match "real" taxonomy. So, for example, they list roebelinii as a species (and many others that lumpers would not consider a species). I find, for example, that roth x philippinense is St. Swithin. Nothing surprising about that. I also know that growers sell roth x phil var. roebelinii as St. Swithin. I also don't find that the RHS has registered roebelinii x roth, either as St. Swithin or as something else. Do they have a list of synonyms that they use in registration? Can this be found anywhere in Wildcatt? When doing the hybrid checking, I don't find that the computer will make the "conversion" and list roebelinii x roth as St. Swithin. Is just says, "hybrid not registered" (while at the same time listing awarded St. Swithins with roebelinii as one parent). Is there some trick I'm missing here?

Confused in Berrien Springs!

Harv

Hi Harvey,

Microsiemens to PPM presents some problems, some natural and some manmade. PPM for individual salts can be directly converted, eg at 20 degrees C, MgSO4 1ppm=0.80 microsiemens/cm, MgCl2 1 ppm=1.7 microsiemens/cm, (NH4)2SO4 1ppm=1.5 microsiemens/cm, urea 1ppm = 0 microsiemens/cm. This obviously presents a problems with complex fertilizers. All of the meters we use measure conductivity, some just use an "arbitrary" conversion to PPM. I have not been able to determine if there is a standard "arbitrary" conversion factor. An old lab meter I have that has dual scales states on the face that the PPM is "NaCl equivalent", which would mean that for PPM, microsiemens was divided by 1.64. I tested one of my newer meters against a "1000 PPM" standard and got a reading of about 1750 microsiemens/cm, so my best guess is you would have to divide my readings in microsiemens/cm by about 1.7 to get the equivalent readings in PPM for your meter.

According to tables in Bob Gordon's Orchid Seedling Care, 1/2 teaspoon of Epsom Salts per gallon of RO will give you about 50 PPM Magnesium, somewhat above the 6 to 24 PPM he recommends. 1/2 teaspoon Calcium Nitrate per gallon of RO water will give you about 100 PPM Calcium, within the 40 to 120 PPM range he recommends. Again I adjust, if necessary, to a pH between 6.0 and 6.5.

As far as adding tap water back to RO, it probably isn't a bad idea. I know some growers regularly remix 10% tap water. I don't think it is for the calcium, but rather to make sure that some elusive trace mineral that we don't even know is important (eg. some plants have been shown to require sodium in low levels). For calcium to even be available in the tap water it needs to be in the acidic pH range. We don't routinely add tap water back, one of the components in our area is sodium, but do once in a while (usually when we are short on water).

As I understand it GE Chroma 50 lights and the Phillips C50 are essentially the same, with a 5000K spectrum. We used the GE bulbs for several years, but switched to the Phillips a couple of years ago. We can buy the Phillips for less, and they have the C50U (Ultralume) available, which produces about 40% more lumens for the same energy input.

Not too many comments on spelling of species, except with the note that there are some disagreements there (ie Paph. fairieanum x Paph fairrieanum), big surprise there. As far as I know only Paph. philippinense is accepted for registering hybrids from this group. Even more confusing are concepts such as Paph. glanduliferum vs praestans. Currently only Paph. glanduliferum is accepted for praestans, glanduliferum, wilhelminae, gardneri, bodegomii etc. I am not trying to claim these are all valid concepts, just that Paph. praestans was accepted for registration for many years, but now only Paph. glanduliferum is accepted. I think that WildCatt has in it any name that has ever appeared in registrations, and it would be an improvement if they were cross referenced.

Bob

(The following comments are in response to a post by a Paph grower who experienced better results using tap water than rain water. This discussion took place on the PPP list (Paph and Phrag Pollen Exchange) list run by Harvey Brenneise . Although there is some duplication of membership between these lists, I am sending it out for the benefit of those on this list only.)

You don't say what you were using for fertilizer, or what your pH of your rainwater/fertilizer irrigation was. Using pure water will tremendously enhance plant quality, but only if you use it as an opportunity to replace all the needed nutrients in the proper balance, and at the proper pH. Rainwater in our area can range from about pH 5.8 down to around 3.0 to start with, and then addition of acidic fertilizers can then make the problem worse. Low pH's will put a collection into decline over a period of time, and will eventually kill most of the plants (someone we know had this experience). Also, with pure water sources you need to properly feed back all macro and micro nutrients. Some people look at blending some tap water back as "insurance" that they are doing this, but it is sort of like buying insurance from someone you don't know without reading the policy, you don't know what you are getting. Our approach is to start out with a clean slate, and then add everything in the desired proportions, and control the pH. I can't stress the following enough, if you don't pay close attention to complete and balanced nutrition and pH, then either do not use pure water sources, or blend them with tap water. If you want to grow everything closer to its full potential, then the trouble of complete nutrition and pH control will fit the bill, and even the more difficult plants like sangii, mastersianum, bougainvillianum, wentworthianum etc. will grow and flower easily.

I also don't recommend the use of lime on potted paphs. First, not all will appreciate it, some may outright resent it. Second, it will wash through creating a transient very alkaline condition, which is not desirable, and then wash away without any long term benefit. If you control your pH of irrigation water to 6.0 to 6.5, then we suggest a top dressing of crushed oyster shell on the limestone loving paphs. This provides a slow time release, and you can see when to add more to the tops of the pots.

> Hi Bob: I went to the Washington DC Paph Forum a few weeks back & had the good fortune to be the first person to find the sole plant of P. mastersianum. Several folks there said that it is a reluctant grower & bloomer. Would you have any suggestions as to how to help this new addition grow well for me? I grow under metal halide light sin the basement, & mix part tap city tap water & part deionized water. Thanks, Dan

Hi Dan,

Paph. mastersianum is a good example of the old adage, grow the roots and the plant will follow.

You've been getting the posts on water quality, so you can refer back to those as you need to, and that really is one of the most important factors in growing P. mastersianum, they do not want any salt buildup in the mix. I also occasionally, as in every third to fourth watering, use plain RO water on the Paph. mastersianums, more frequently than for most others.

The next is mix: I use xtracoarse perlite, NZ sphagnum and fine and medium bark, to give the plant moisture but also air at the roots, even after watering, so that after 3 or 4 days, the roots have to search a little bit for moisture but are not completely bone dry. You might have to water a little more often with this method, but given the rarity of the plant in question, a little more work doesn't seem much of a trade off when it flowers! A good test of the mix would be as follows: after the plant has been firmly potted water with a good steady stream of water, the water should flow evenly through the pot with no bubbling or build up on the surface. If this occurs the mix is too dense.

If you think that you have the mix correctly formulated for the plant and root mass in question, you might also carefully unpot the plant after 6-8 weeks, shake the mix off and see how healthy the roots appear. If you have soggy roots that you can slip off the plant in question, your mix is too dense, and the roots need more air. If you have healthy new roots started, congratulations! You are on the right track. Carefully repot the plant back into your mix, (or you could use the old mix that you just shook off the roots) taking precautions not to damage the white growing root tips. On the other hand, if you have rotten, squishy roots, I would let the roots dry out for several hours, or overnight, gently slip off the dead roots *but* leaving the interior wiry part of the root intact if possible, and pot down in size so there is a very tight fit between the remaining roots and the pot you decide to use. If you have completely lost all the roots, you can probably still save the plant by fashioning a 'U' shaped wire form, hooking that upside down over one of the lower leaves to provide stability to the plant while it is growing new roots, and potting in a very small pot with your mix. The plant is then placed in a large zip lock bag with some moderately damp moss lining the bottom of the bag. Partially seal the bag, then exhale into the bag filling it to capacity with your breath. Place in a warm, moderately bright spot and wait several months, checking on the plant every few days and refilling the bag with your breath. Roots should eventually start, and then you can slowly begin opening the bag to allow less humid air inside, and then when you feel the plant has the ability to join the rest of your collection, you can remove it from the bag.

Light should be bright but not so much that a hand placed over the plant will throw a decided shadow. Also, high humidity is a plus for this species, as is good air movement (so that tall stems will be seen to move with the air flow). We weren't completely happy with our limited experience using HID lighting as a sole light source, but that certainly doesn't mean that it won't work well. I think that if I were to go back to HID (except as supplemental greenhouse lights), I would probably try a mix of SonAgro High Pressure Sodium and Metal Halide. We do grow several Paph. mastersianums under fluorescent lights, with the leaves about 4 inches below 4 C50 Ultralume bulbs, and they are growing and flowering very well.

Paph. mastersianum will frequently self, so hybrids should be made on another plant. BTW, seedlings of this species from flask have been very sturdy and extremely good growers. Hope this helps. Lynn