Can I plant anything in potato patch after blight?

Just got potato blight and cut all tops off.

Some of the plants have a few small new potatoes, so I'll probably just pick them all and have a few meals out of them It's a real shame, because there were lots of lovely healthy looking small tubers on the roots.

If I then turn over the soil, is there anything I can plant now (not necessarily from seed). We're in northern france.

I've got lots of friends who might donate small plants, think options might be squash, cabbage, brussels sprouts, beetroot, courgette, lettuce leeks, beans.

I know it's late, but hoping not to waste all my potato patch if there was something I could get out of it.

What's immune to blight?

legumes. You should be able to plant beans and get to a crop before fall, but if not plant it to clover to get green manure.

Make sure you get all the potatoes out so blight doesn't overwinter in the bed.

I would think you could plant anything not in the potato family (which includes tomato, pepper, eggplant, tobacco.....); and which you would have sufficient growing season for. Normally potatoes like high nutrients, so chances are, if you're an experienced gardener, you will have manured/composted that area thoroughly and your failed potato crop hasn't used much of the nutrients. So you might do well with another relatively nutrient-hungry crop (brassicas, greens, squash?) as opposed to legumes.

Thanks for advice, just for my information - why not legumes?

Would beetroot be OK?

Dave Quinn wrote:Thanks for advice, just for my information - why not legumes?

Would beetroot be OK?

You can plant legumes, it is just that you shouldn't NEED to because the potatoes didn't use up all the nitrogen.

If it was Fusarium oxysporum, I would say plant mustard. I have had great success ridding my soil of that pathogen by planting mustard and turning it under.

If it's Phytophthora infestans, the agent of late blight, I don't know if the mustard will be as efficacious. Fusarium and Phytophthora are completely different critters and the sulfur compounds that kill the fusarium may not do anything to control phytophthora. Here is a paper that talks about jasmine being able to stimulate a defensive response to phytophthora, but it's not very conclusive.

Can you tell us more about the symptoms? Are you sure it was late blight? Has the weather been very wet lately?

Not sure which, one day loads of good foliage, couple of days later some totally dead, lots with brown/grey dried leaves, can't see any fungus underneath leaves.

Quite a few of the plants had potato fruits on as well, which I've never had before.

Been clearing vegetation and there's a small crop of tiny new potatoes which look lovely, and the roots have loads of tubers starting. So close and yet so far - when I think of the effort it's a bit soul destroying really

Dave Quinn wrote:Not sure which, one day loads of good foliage, couple of days later some totally dead, lots with brown/grey dried leaves, can't see any fungus underneath leaves.

That sounds more like Fusarium, Phytophthora can be seen on the leaves, whereas Fusarium attacks the stem and vascular structure, drying the plant out like it was set next to a blast furnace.

I'd say try the mustard treatment. While Phytophthora is fairly specific to potatoes, Fusarium attacks a lot more plants. I just lost some beans in a new bed that I didn't know was infected. That new bed was not in a part of the garden where I regularly have mustard growing. I hoed out a trench, filled it with some thin mustard leaf puree, and replanted the beans. The new ones that are coming up now are looking much better. I also planted a companion row of mustard behind the bean trellis so that the bean roots can intermingle with the mustard roots. All parts of the mustard plant produce the sulfur containing compounds that are toxic to Fusarium (and give the mustard its bite). By tilling mature plants under, you leave enough of those compounds in the soil that the Fusarium, which can persist for a long time, will be knocked down, maybe permanently.

THANKS, John.

Mustard is going into my cover crop mix.

Does it have to grow in the affected bed? Or can it be grown elsewhere and brought in as a mulch? Does the benefit carry over if it is composted first?

I've been advised to spray with bordelaise next year before the blight season. I've been advised its completely organic and just helps to prevent the blight. Can anyone confirm or put me straight.

I'm putting in Mustard for cover crop as well!

I think you mean Bordeaux Mixture. I wouldn't call it "organic", since it contains no carbon atoms, it's just copper sulfate and lime. Being a pedantic chemist, I put those in the "inorganic" category, but they are completely natural and not something to be alarmed about.

However, Bordeaux Mixture is a topical treatment for the leaves of perennials. While it will knock down airborne pathogens that land on new leaves in the spring, it doesn't do anything to combat dormant spores hiding in the soil, which is what I think your problem is. Still, if you have trees or perennial vines in your garden, it couldn't hurt to give them a spray next spring, right before they are about to bud out.

R Scott wrote:
Does it have to grow in the affected bed? Or can it be grown elsewhere and brought in as a mulch? Does the benefit carry over if it is composted first?

Growing it in the affected bed is better than using it as a root drench, which is better than using it as a mulch, which is better than letting it compost first. Those sulfur compounds in the mustard are gourmet food for bacteria, so after they get done composting it, I doubt much benefit would carry through.

I was so irritated by the results my first year here that I broadcast a pound of mustard seed in a 4000 sq ft garden. That's a LOT of mustard. I did that around October and by January my garden was knee-high in mustard. My neighbor was nice enough to come over and disk it under for me and then I spread a couple inches of well-rotted wood chips over the whole thing. The combination of all that mustard and lots of new fungi annihilated the Fusarium. Like I say, I still have it in other places on my property, and it is a rather ubiquitous microorganism, so I don't have any illusion that I can eradicate it from all parts of my garden, but I can sure put up the UNWELCOME sign.

I still get volunteer mustard popping up everywhere, and that's just fine with me. I don't mind having "weeds" with a purpose to them. Now if I could just find some useful purpose for bindweed and cudweed....