Friday, May 1, 2009
I’m going to leave fertilizing for a week or two, although I have had a very good enquiry about composting so I’ll get back to that soon.
I was giving a garden club talk this week and the question of “damping off” raised its ugly head. The poor lady asking the question didn’t even know what the problem was but she had spent good money on punnets of seedlings only to watch (some of) them slowly die, before they even got started. We have had a similar problem with large landscape plantings too, ouch!
Have you ever planted seedlings and had them just sit and not grow? Have you ever checked the roots of these plants? Always start with the roots. Often Pansies particularly will just sit and go nowhere, if you pull on the top of the young plant it will just come away from the soil with no roots attached. A root rotting disease has eaten the roots away. See the image above of young Soy Bean seedlings.
The most common form of the problem with flower and vegetable seedlings is a fungus called Pythium. Often it will cause no obvious problem, but if your plants are stressed say having just been pulled out of a punnet and squashed into the ground or planted during very hot or very wet weather the fungal spores have the opportunity to attack.
What are the solutions? Minimize plant stress! Start with strong plants with a healthy root system. Yes you should check the roots of any plants you buy. If possible, water your new seedlings in with a fungicide called Fongarid. Fongarid comes as a powder from your garden centre. Add some to a watering can and water your plants in with it. One application should do the trick. Treat Fongarid with the care you would any gardening chemical, but I am confident it is safe to use, it doesn’t actually kill the fungi, it provides the plant roots some protection.
What else can you do? Fungi like Pythium live in the soil. I don’t recommend fumigating soil (nasty poisonous stuff), so you will need to apply the Fongarid every time you plant out once you have found your soil is carrying disease. If you are growing in containers, throw out the old potting mix and wash your pots with chlorine solution, household disinfectant will do fine.
If you are really interested in Pythium, follow this link. I haven’t used the product ‘Re-bound’, but it is a chemical related to Fongarid and they give some really good background on Pythium.
Oh and if you are really keen follow this link to Wikipedia there is a list of the Pythium species as long as my arm.