I have recently built an herb spiral and on Monday, I planted the herbs at the lowest part of the spiral and watered them well. Today is Wednesday morning and the soil is still very moist. It's supposed to stay moist at the bottom of the spiral, but I'm wondering if it's too moist. The spiral gets about 6-7 hours of sun a day, but we had a cold front come in yesterday, so that could be preventing evaporation.
I know there's an herb section, but this question isn't really about my herbs, it's about the type of raised bed I put them in. Thanks.
I had never even heard about them before, so don't have knowledge of that. But I do have some knowledge of herbs, and most herbs do not like to stay moist.
Looking at the diagram above, it seems that the trick is what you plant where. The water tends to flow downward, so as you noted, it will be more moist at the bottom. So they put watercress at the bottom, and then mint which likes to stay moist. with the drought loving herbs, sage, tarragon, rosemary, oregano at the very top.
So I think your question really shouldn't be "is it too moist?" but "what can I plant in the bottom area where it tends to stay moist?" Mint is an obvious choice, but then you would need to put a barrier between it and the next thing or it will tend to take over the whole spiral. Comfrey and angelica are other choices for the moist area.
Last edited by rainbowgardener on Wed Oct 19, 2011 11:42 am, edited 1 time in total.
I have my mint at the bottom of the spiral, I also have my dill and parsley toward the bottom. But even these herbs that like moist soils still like those soils to be well-drained, don't they? My concern is that I placed the spiral on a patch of dry, dead lawn, and I worry that the soil under it might have become a hardpan that won't let water drain away.
Thank you for the suggestion about comfrey! I wanted to include it in my spiral, but didn't know that it prefers moist soil.
Oh, and thank you for posting that picture of the herbs' placement on the spiral. I'm happy to say that the herbs I have in common with that picture were planted in about the same place in my own spiral. Though I wasn't ambitious enough to include a watercress pond.
Watercress will grow in a pond, but I think it will also grow just in soil that stays consistently moist. Most things like well drained, but any of the marsh/ bog type plants will be fine with damp all the time:
Herbs for water
I have many favorite wetland herbs. Water mint (Mentha aquatica) grows in water up to 3 inches deep, and lilac flowers on stem tips are attractive to bees. The tastiest mint of all, pink- or white-flowered M. spicata ‘Kentucky Colonel’, grows in moist soil as does bee balm, whose leaves make a rather pungent tea. I particularly like the lavender blue Monarda ‘Blue Stocking’, rose-pink M.‘Croftway Pink’, and brilliant M. ‘Cambridge Scarlet’. American mountain mint (Pycnanthemum flexuosum) spreads throughout my soggy hillside, with white bracts lasting for two months in the summer. (You can also use its leaves to make a tea.) Bog sage (Salvia uliginosa), with the softest baby blue flowers and a long season (April through October) of bloom, is another winner for moist soil that can also be used to make a digestive tea.
Yours isn't probably a bog, but any of these would also grow in non-marshy but consistently moist soil. The bee balm is very adaptable to wet or dry and comes in dwarf versions that wouldn't get tall enough to shade other stuff out-- and bees and butterflies love it and it is great in herbal tea mixtures! What more could you ask!?
