Question

soil blight 1   QUESTION: Beginning of June I built a large flower box inside a greenhouse and moved my carnivorous plants inside. A strange cottage cheese looking, tan/brownish mold is starting to grow on the soil surface in the area of the VFTs. It's light tan, slightly crusty, mushes when squeezed with my fingers. It is slowly moving along to the opposite end of the box. I don't notice it on the VFTs, but nearly all the VFTs are experiencing numerous leaves suddenly turning black at the ends of the traps and progresses down the stems toward the rhizome. I've sprayed it a couple times with Neem oil, but no luck. I'm very concerned that I could lose my whole collection.

I keep the soil pretty moist, using RO water, high humidity, good amount of sunlight, but there might not be much air flow.

Attached is a picture that shows the pest in question.  Note: I took this picture off another website for reference.  They do not have a definitive answer, so I thought I'd ask you guys! Thank you much for your time and any insight you can offer.

ANSWER: Hi Riverhigh,

This doesn't look like fungus, but mineral deposits that often form on the surface when it's very warm with lots of evaporation.  Even if you're using R.O. or distilled this can still form from organics in the peat moss.  This and the problem with your plants are probably only indirectly related.

Your set-up descriptions sends up a couple red flags.  Your flower box, what is it built out of? Does it have drain holes in the bottom?  Sometimes people think since cp like to be wet you can grow them in undrained containers.  This often leads to failure due to bacterial build-up and lack of oxygenation of roots.

You mentioned "good amount of sunlight".  What does that mean?  Two hours, three, indirect sun?  Also humidity and not much air flow; is that just from being in the greenhouse, or are the plants in some kind of enclosure?  If you could send me a photo that will help immensely.  Take a picture of your growing set-up with your plants.  This helps me to much better access what may be happening to your plants.

Good Growing!

Jeff Dallas
Sarracenia Northwest
http://www.cobraplant.com

---------- FOLLOW-UP ----------


greenhouse   QUESTION: First, thank you for taking time to look at my question. Here is the additional information:

The box setup: is made of plywood, with a water-resistant application applied, covered with a triple layer 4-mil plastic. It measures 8'x12"x12". At no time does the soil contact the wood. There are no drain holes, but there is about 4" to 5" of pumice lining the bottom of the box.
Soil: 2 parts peat to 1 part rinsed playground sand.
Water: reverse osmosis

The greenhouse gets about 5 hours direct light. I'm located about 5 miles from the coast in San Diego - warm days/cool nights. I've started keeping the window flaps open all day and night, so there is plenty of fresh air circulating.

Attached are pictures with captions. As you can see the plants are all showing signs of stress. I've treated them with Garden Safe Fungicide 3 neem oil as well as Ortho Ecosense 3-in-1 rose and flower care sulfur spray. I've had problems with aphids and spider mites in the past.

I've grown VFTs for years in stand alone containers with lots of success, so this is quite perplexing. My whole collection, including the sarracenia, is slowly dying and I don't know what to do.

I have thought of digging up all the plants, rinsing them, and replacing the soil, but without knowing what is causing the plants ill health, that's just a stab in the dark. Thanks for any help you can offer!

ANSWER: Hi Riverhigh,

If all your plants are suffering, then it screams that your planter is the problem.  It needs to be able to drain freely.  You're probably loosing your plants to root rot from lack of oxygenation in the soil and bacteria build-up.  Also, your flytraps look exactly like flytraps grown in terrariums.  Monitor your temperatures in the greenhouse.  If it's getting above 90 F in there open the greenhouse up more.  It could a combination of high-heat during sunny periods combined with the lack of drainage in the planter.  The mineral deposits on the soil surface you've seen are also more prevalant in an undrained container since these would normally be washed away are precipitating to the surface.  In addition, even though reverse osmosis takes out most of the minerals, it doesn't remove all of them.  In a closed system, they will build up.  If your water is very hard already, the r.o. unit may leave a significant amount behind.  Here at the nursery our water is about 120ppm, and after it goes through the r.o. unit it is about 15ppm, so there is still some mineral there.

With your pesticides, be sure to spray those in the evening.  Many products say not to use them during high heat.  This is especially true of sulfur products.  It really seems in your situation that it's not any kind of fungus harming your plants, but the conditions.

I'm curious why you moved your plants into a greenhouse if they were doing well outside?

Good Growing!

Jeff Dallas
Sarracenia Northwest
http://www.cobraplant.com



---------- FOLLOW-UP ----------

QUESTION: Jeff, thank you so much for your detailed reply and sorry for the delayed response. I took your suggestions and drilled 5 holes in the bottom of the flower box. I also replaced all filters and the membrane in the RO unit. I did this about 3 weeks back. Since then, I have flooded the flower box nearly twice a day with fresh RO water to get oxygen to the roots and flush out bacteria and minerals. I also trimmed away the dead leaves. I am thinking you were right on all counts. I've been really hoping the VFTs would rebound and by all indications they are! The ones that looked nearly dead are slowly getting some new, healthy leaves, and the others are looking nearly as vigorous as ever. The S. Leucophyla don't seem to have changed, but the white trumpets are sending up lots of new leaves, as I understand they do at summer's end. What you identified as mineral deposits seem to have nearly disappeared.

Question: what do you suggest to help the VFTs that were affected? transplant them into small pots? leave them alone?

To answer your question about putting them into the greenhouse: I was having the EXACT same problems I originally described in my first post(wilted VFTs, mineral deposits on surface). As I said I used a large children's wading pool as the liner, but WITHOUT holes. It didn't even occur to me that the plants in the flower box began to look just like the ones in the little pool. So...drainage seems to be extremely important, even if one lines the bottom of the container with several inches of pumice. Also, I moved the plants inside the greenhouse because I sit in there a lot and couldn't see my outside bog garden from inside. Another thing is VFTs and sundews at ground level look really small when I'm standing up.

Thanks again so very very much for your help, Jeff. At this point I'm thinking you saved my collection. I really was at a dead end. A couple more weeks should determine if your suggestions really are on the money, but I'm thinking they are from what I can tell so far. The growing season is a bit longer where I live in San Diego than in other parts of the country, so I should have lots of fun watching them.

Answer
Hi Riverhigh,

Your welcome!

I would say that if the plants are starting to recover, just leave them be.  Transplanting would just cause more disturbance.  One watering with a Superthrive solution could be of benefit since you may have had some root damage.  Be sure to follow the directions on the bottle for dosage.

As we approach fall and the weather cools some you should be seeing your best leaves on plants such as Sarracenia leucophylla.

Good Growing!

Jeff Dallas
Sarracenia Northwest
http://www.cobraplant.com