Planting alliums after alliums

Hi,

How important is it to not plant alliums where alliums grew before. I am planting my winter onions, garlic, shallots, multipliers, and walking onions right now, and ran out of space in my new raised bed. I have another bed free, but it's one I grew onions in before. I have heard I should not follow a planting of onions with more onions or other alliums. Just how important is that?

Thanks!

essentialplanet,

Not a good idea. Crop rotation is very important to avoid disease. You should wait at least one year before planting onions where onions have grown before. That's really important to avoid the onion maggot and other nasties. Just my opinion, but I would plant something else there besides onions and garlic.

Arias

It depends on where you live. I have planted my onions every year in the same spot for several years because they love that bright sunny spot.. I have never had an onion maggot, but I suspect our cool dry climate discourages them. So, it aint necessarily so.
I am a great believer in crop rotation, but I also find my tomatoes prefer one spot over another, no many how many years I have planted tomatoes there.
I don't get it, but that is what happens in my garden.

Thanks to both of you for your input. I guess experimentation may be the order of the day... though I can't claim a cool, dry climate...

Also the onion family are heavy feeders, and that's another reason for crop rotation. If you do decide to plant them in the same bed, dig in some compost or peat moss. No manure. None. For some reason the alliums have more disease and insects in soils that are loaded with manure. Even manure that has been aged. Who knows you may beat the odds of not rotating. It's worth a chance, and that's what gardening is. You plant, and you take your chances. But I would kick the soil up a notch with some compost or peat moss or finely rotted leaves. Something organic to get them through the long growing season.

It may be my cool dry climate but I fertilize my onion bed highly with compost made of about half horse manure and half leaves and pine needles. I don't claim it will work for everyone, but I agree that they are heavy feeders.

Hello Pajaritomt,

How I envy you living in a cool dry climate. My home state feels semi-tropical these days. I'm a fan of manure in compost and as a top dressing when it is well aged. Because NM is so dry and cool does it take a long time for organic materials to break down? Just curious. And how do the moisture loving alliums mature in a cool dry climate?

I don't think it takes very long for horse manure to break down, but leaves probably take longer and pine needles take even longer. But adding water to the compost makes all the difference in speeding it up. Onions grow very well here and we don't seem to have the insect problems you have. We have to grow intermediate-day onions, but that is related to lattitude, not heat. We do have to water our onions, of course, because they do love water.

I may still take your advice Arias, and stay away from planting the garlic in my onion bed. I am looking at other options - would rather not set up a good breeding ground for disease...

Crop rotation is a great idea, usually. I think it is a good guiding principle unless you have evidence to the contrary.

I have raised beds. My favorite and the largest will lay "fallow" next summer. I have planted tomatoes, onions, beans, greens, cabbage and Swiss Chard in it over the past 6 years. It needs a break, so next year it will rest [covered] with a layer of rotted leaves and aged rabbit manure. Everything improves with a rest, including soil. You know, when I give my opinion to my fellow gardeners, it's just that~ an opinion. There is no method but the tried and true one. So, you could experiment with the bed and go ahead and plant the alliums. Nothing is written in stone. It could be your best harvest yet. Happy Autumn.

Arias

Hi Arias,

True that!