Premium soil/mix stays damp...forever.

[stromato]

I've recently had to leave small bare root plants transplanted into small (3-5 inch) plastic containers and some small smartpots in conditions I have no experience with for container gardening: temps constantly in the mid 60's, never above 70, and usually cloudy, maybe an hour or two of early morning direct sunlight. The humidity stays around 50%. I've used “premium” soil (ocean forest) or mix (pro-mix with perlite added). The containers have good drainage and were never left standing in water.

Although under these conditions I expected very low evaporation rates requiring much less frequent watering, I was surprised to see that after watering only once at the time of planting, the soil and the mix stayed moist, even at the surface, for weeks. In the case of ocean forest that white fuzzy fungus formed on the surface of the soil four days or so after planting. Under these conditions, the “premium” media appears to be behaving just as badly as the miracle gro moisture control stuff.

The plants did not like this, the roots perhaps not receiving enough oxygen even though upon inspection the roots were never slimy or rotten. Some did not survive.

So I'm wondering if this problem is familiar to experienced container gardeners, and what media would work under these conditions for bare root plantings?

I'm considering trying gritty mix or that 5-1-1 mix, which I've never used before, but since Turface retains water and I'm dealing with bare root plants I'm not sure if that would work.

Thanks for any advice anyone may have.

[RayR]

An hour or two of direct morning sunlight is not enough to keep those (tomato?) plants metabolizing and transpiring water through the leaves. Aren't you using artificial lighting?
Even evaporation is going to take a long time without some warmth when the humidity is high enough. What is the soil temperature?
The white fungus is just enjoying the conditions it loves—low light, plenty of moisture and a rich food source.

[stromato]

Thanks RayR,

Yes, there is artificial light. Humidity never gets above 50%. Soil temp would be close to ambient temp.

Plants rather quickly show some abnormalities similar to those I've seen in plants under “normal” conditions in so-called moisture control media that retains too much moisture: browning or darkening along the edges of leaves, etc.

[amideutch]

Ocean forest is a little hot for seedlings. I've used "Light Warrior" for transplanting seedlings
into 4" CowPots with no problems. Also the CowPots will wick some of the moisture from the growing medium and excessive moisture retention and fungi have never been problems for me. When the seedlings are ready to be transplanted they are done as a whole as the CowPots being made out of cow dung and are biodegradable so there is no transplant shock.

Ami

[RayR]

I've never used a moisture control potting soil, so no comment there. I do use Ocean Forest and have used Pro-Mix, neither of which I've thought of as having a high retention of water, especially in small pots, so I'm a bit puzzled why yours is staying so wet and the leaves are browning at the edges. Did you add anything else to the media, fertilizers or whatever?

[Doug9345]

Are they outside where the are getting rain and dew on them? Just heavy dew and no sun can keep a pot soaking wet. I assume that, with the plants getting an hour or two of sun a day, you are just trying to keep them alive until spring.

[Ed of Somis]

I am glad to see people are still interested and talking about their maters in late Nov! The opposite of moisture control (retentive) mixes...are things like cactus mixes. I will try these next Spring...mixed in different ratios with compost and standard soil mixes. The gritty mix is way too "open" of a mix for me. It requires constant watering/feeding in a semi-dry climate.

[amideutch]

I am glad to see people are still interested and talking about their maters in late Nov!

Shoot, we talk maters 365 days a year.

[tlintx]

Some of us still have plants out there.

I think it's the peat. It's so powdery now... on the lookout for a good sub for next year.

[stromato]

Ty for your replies.

No, I did not add anything else to the media. Indoor location.

I remain surprised that this media, including the surface, has stayed damp for so long in such small containers.

One could theorize that under these conditions (are they really that extreme?: 63-65degF with plenty of light but essentially no direct sunlight heating the soil surface) that all “premium” peat-based media performs badly.

Cactus mix might do better with the moisture retention problem--I've never used it--but I have not seen anyone around here recommend it for growing anything other than...cactus.

Thanks again for the suggestions.

[Labradors2]

Hi Stromato,

If the plants were mine, I would take them out of their containers and gently remove as much "soil" as possible, before re-planting them in a container mix with no moisture-control granules.

That cactus mix sounds good. Who'd have thunk it?

Linda

[Urbanfarmer]

I wonder if your mix is heavy on coir? It stays damp forever. We've had trouble with it if it is too large a part of the mix. It works great for us if the total is no more than 20%.