[makedoandmend]

Folks,

Despite attempts to avoid it, I suffered two episodes of damping off with parsnips last year.

Cheshunt compound is no longer available (thanks europe!)and I am yet to be convinced that 'new' replacements will be as effective.

This year I have built a temperature and humidity controlled propagator and would like to find out what humidity level is safe.

Looking on-line, lots of articles say that high humidity is a problem but none of the articles are very specific, or give a evidenced based account of 'damping off'

Can anyone shed any light on those fungal diseases which cause damping off and 'safe' humidity levels to prevent them?

Any links or info. would be much appreciated.

Cheers,

Make do.

[DD.]

Do I read this correctly in that you're germinating parsnips in a propagator?

[Aunt Sally]

I always sow my parsnips directly into the ground. They don't need germinating in a propagator.

[DD.]

My point exactly, in fact they'd positively hate it - as you've found out!

[sarajane]

My point exactly, in fact they'd positively hate it - as you've found out!

I'll second third and fourth that. Straight into the ground

[Trillium]

Agree about the parsnips - ground only.

but generally, damping off is simply too much water, too often, with little air circulation, and likely poor bottom drainage. The fungal mold has an easy time starting up.

I use cooled camomile tea over the surface to control damping off if it occurs; mostly I watch my watering.

[TheSpartacat]

Ok, so- you're saying you built the propagator this year... and you had damping off with your parsnips last year... so you're not actually saying that you had your parsnips in a propagator
(...that would be the wrong thing for parsnips as others have mentioned...)

I've not used a temperature/ humidity controlled propagator (i tend to use the plastic baggy method which is unscientific) so i couldn't give you a gauge reading on what you should keep yours at, but as Trillium says, too much water, poor drainage, bad circulation contribute to damping off.

I use chamomile tea as well... and watering from beneath can be good too... or a light spray from a water bottle to just moisten the soil rather than soak it!

[DD.]

Whether or not a propagator has been used in the past, damping off is also associated with warmth, which parsnips do not need.

I'll ask the old question. What did it say on the packet as to how to propagate them, how does this compare to how you did them?

[makedoandmend]

Folks,

Last year I did the tall paper pot trick without a propagator, and did end up with some good specimens, nice straight roots, sweet, tasty. Other than an aphid attack with some of them I think I did rather well.

Logistically I have to start everything off in a small free-standing 'green house' (which I use to harden things off since it gets no sun until late spring early summer) or propagator and have it ready to drop into the garden when the weather breaks. My garden is North facing and not a single part of the garden gets sun for more than a few hours each day even in the height of summer, due to surrounding buildings.

Added to this my garden is solid, cold wet, clay (although it is slowly improving) and I have a very restricted space for cultivating anything.

If I start things in a propagator, I can be sure of filling the garden with good specimens.

In short, I have far from ideal growing facilities and have to do everything I can to maximise cropping.

It may not be how others would do it but, given the same circumstances, others may find they have to adopt similar 'unconventional' methods.

If I could return to my original request - can anyone tell me what a 'safe' humidity level is to prevent damping off?

Regards,

Make do.

[Aunt Sally]

Ah, I see you don't have an allotment but are growing in a small garden with poor soil. 

The more ventillation you can give your seedlings and veg plants the better they will grow.  Vegetables in general like good spacing, good drainage, full sunlight and fresh air.

[sunshineband]

There wll be no straightforward 'one answer' to your question, makedoandmend.

Damping off is caused through
1. Poor drainage
2. Too humid conditions with insufficient ventilation3. Allowing entry to stems through damage


So firstly try to make sure compost is free draining -- you could add vermiculite, for example

Then make sure that you have well ventilated conditions, despite bottom heat

And water carefully from below so that the seedlings have no chance of being flooded
 
And lastly, keep the warmth of the propagator for plants that need heat for germination (look at the back of the packet) Other are fine without being covered up or kept warm

I've repeated some of what others have said, to try to being all this together for you

Hope it helps 

[Trillium]

Very specifically, there is no humidity level suitable for starting seedlings. And most of us have to make do in some way.

Root crops like carrots and parsnips simply don't like being started in a propagator; they prefer nature to tell them. They also don't like their roots being moved so the paper pots is a good starter idea but they'll quickly outgrow them so keep a close eye on them.

Other plants aren't so fussy in the propagator, but do keep any humidity levels low. As you've seen from the postings, damping off appears when things get damp.

[makedoandmend]

Folks,

I have done another web search and haven't really come up with anything except;

Rhizoctonia spp. prefer 15-18 C - No %RH given.

I can't find anything specific to Pyhtophthoria or Pythium spp.


I shall therefore monitor temperature and %RH, and report back on my outcomes.

Thanks for everyone's input.

Make do.

P.S.

I have already adopted the vermiculite tip following advice from some of the 'old hands' at my allotment / garden association.

ALL plants are bottom watered on a strictly 'just moist' basis .

Although the parsnips may be in a propagator their temperature is controlled HOT and COLD.








Reference to an illegal plant removed

[gobs]

Folks,

I have done another web search and haven't really come up with anything except;

Rhizoctonia spp. prefer 15-18 C - No %RH given.

I can't find anything specific to Pyhtophthoria or Pythium spp.

I shall therefore monitor temperature and %RH, and report back on my outcomes.

Thanks for everyone's input.

Make do.

P.S.

I have already adopted the vermiculite tip following advice from some of the 'old hands' at my allotment / garden association.

ALL plants are bottom watered on a strictly 'just moist' basis .

Although the parsnips may be in a propagator their temperature is controlled HOT and COLD.

I thought you were growing parsnips.

I find this damping off more common in cooler conditions, with earlier sowings.

Also: make sure pots and soil are clean and good, water with fresh tap water.




Reference to an illegal plant removed