Food forest advice for wet climate

Hi, I’m hoping to get some advice for my food forest (especially fruit tree spacing and planting) from anyone who lives in, or has experience temperate, wet climates that have mildew issues. If anyone has experience creating a food forest in this kind of climate, I'd love to hear how you did it and how it's going. I have several apple, cherry, asian pear, filbert, and plum trees that are waiting to go in the ground. I’ve prepared the planting area over the last 6 months with cardboard, woodchips, compost to kill off the grass and hopefully start improving the clay soil. For nitrogen fixers I have a seaberry, various plants, and the north side of the planting area has red alder trees already, which I’ve heard work for nitrogen fixing.

Location: SW Washington State
Zone: 8b, Temperate, Wet
Soil: Clay loam

My questions are:


Should I plant the trees in a higher mound to make sure they don’t drown in the wet clay? I’ve received that advice from a couple of different people, but I think the soil will improve quickly using chop and drop, compost and essential microbes.


Should I space the fruit trees further apart than the normally recommended 15ft for semi-dwarf trees? Many people in my area have trouble with powdery mildew and I’m wondering if more space might help prevent that.


Along those same lines – will too many guild plants around the trees increase the chances of powdery mildew for the apple trees?


Should guild plants be planted at the same time as the fruit trees? I’ve been collecting plants for the guilds, but I’m unsure about the best time to incorporate them. The main plants I have are:


Honeyberries
Cane berries
Grapes
Groundnuts
Clover
Comfrey
Mints
Currants
Ramps
Garlic
Hardy kiwis
Walking onions
Chives
Lupine
Violets
Leeks
Daffodils and various other flowers
Asparagus
Rhubarb

I’m anxious to get everything in the ground, but I’m worried about crowding and causing higher humidity around the fruit trees in an already wet climate. We do get some wind so maybe it won’t be as big of an issue as I’m thinking it might be.

Thanks for any advice you can offer, I really appreciate it!

Sounds like a good plant mix. A soil drainage test and observing your high water mark will help answer your mound question. The fruit trees you mention generally need their root crown 2’ above the water table. Ideally they’d be closer to 4’ above. Short term exceptions won’t necessarily kill the tree, but anything over 36hrs of really wet feet (standing water) can be fatal. If you do have inadequate drainage, hugel beds and Woody debris filled trenches for pathways can also help a great deal.

Hi Ben, thanks so much for your advice! Originally I had thought that wood-filled trenches might retain too much water for the area, but after reading a bit more, you might be right. They might just soak up all of the excess water that these trees don't need covering their roots. I didn't realize the crown needed to be that far above the water table - I hadn't read that before, so that's really helpful. Do you think using woody debris to brace the mound might bring too much water close to the roots, or would that work well? We have a lot of limbs that have fallen this winter so I have woody debris that I could use for that as well. Would you plant some of the guild plants at the same time that the trees are planted or give the trees time to settle?

Thanks again, that was very helpful!

Don't put wood anywhere near the trees roots where it will be structural, if you do when it rots and collapses it can take the tree with it.

Digging into clay makes areas where water collects as whatever you put in there whether that is wood or stones or sand is permeable and the surrounding clay is not.  If your ground is soggy year round you really don't want to be holding ANY extra water, so ditches filled with wood/stone and used as paths will help if you have somewhere for the water to flow away. In my climate there is no way to "soak up excess water" as there is practically no limit to the amount of water.

Hi Skandi, thanks for the information! It sounds like we are in the same boat, in regards to excess water. Did you plant your fruit trees in a mound to combat the water, or did you do a different method? I'd love to hear what is working for your trees.

I also have very wet georgia clay with maybe a foot of topsoil. Seasonal flooding for weeks at a time etc..
Over the years I have planted many fruit trees and learned what survives
  Pears, persimmons, pecans and mulberries; they do very well. Floods don't phase them. With a raised bed or hill about 1 ft.  Elderberries, Meyer lemon, turkey figs, arbaquina olives, pomegranate, loquat primocane  blackberries, passion fruit are okay.  I need a 3 ft mound for peaches, avacados, plums and artichokes.
I have tried hugelculture, worked for a few years then logs tired and trees fell over.  It took many years to figure out for me, hope this helps you

Hi Ralph, thanks for the reply, it's very helpful to hear what has worked and not worked for you with your wet clay soil. When you mound for some of your trees, what do you use? Just soil, or do you use a mixture with wood chips? If I mound my trees to keep the roots higher, I'll have to add some soil and since we have a lot of rain here, some kind of border to keep the soil in place. Do you plant companion plants at the same time you plant your trees?

Thanks for the info about the hugelculture, that's good to know! Mulberries might work well here if they like your wet clay - I'll look into that. Not sure if pecans will grow here, but we do have a big old hickory tree that was here when we bought the place. It doesn't seem to mind the wet, although I think it needs some mulch and TLC after all these years. I'm jealous that you get to grow fresh avocados!

I put down a 6 ft circle of wet cardboard down on grass Buy a bunch of cheap 1.79. 40 lb  bags of topsoil,  maybe 10 or so.  Mix that with some sandy soil from my ditch that runs down the side of property,  about a 10 lb block of coco coir and build the mound.
I plant the tree in the middle, add perennials like salvia or something to attract pollinators about a ft. away from tree, around that I pop in comfrey, ( It also loves clay, got it all around property). Then mulch it all over with hay or shredded leaves.  My wife will always pop little plants here and there in those mounds also.  

That is such helpful information, thanks Ralph!

You may have high rainfall, but your summers will be pretty dry.  

If you look around at old farmsteads in the area, see what they did and how their trees have survived.  My grandmother, on the central Oregon Coast, had apple trees (and plums, and chestnuts) that got completely swamped in mounds of Himalayan blackberries after she got too old to keep them cut back.  The deer and bears made paths and tunnels to reach the fruit, but I don't remember there being any extra disease or mildew issues.  Her place was up a valley; it could get windy, but wasn't constant breeze like at the beach.  Grandma's parents old orchard was still producing when I was young, and we picked a lot of fruit out of it.  It was on the riverbank, got almost no sun in the winter, and sometimes flooded in the winter.  But again, the trees were just planted in the ground and seemed to be doing well.  We sure ate a lot of good apples, pears, and plums out of that orchard.  There were the chestnuts I've already mentioned, basically growing as part of the forest, and while they didn't produce every year, they did produce good crops quite often and were very healthy (we think they were a European variety; nobody knew who had planted them.  They were already old when my grandmother was a little girl).  There were also English and black walnuts growing the same way.  So all of these except the old orchard, which was in a cow pasture and got grazed regularly, had a lot of undergrowth, just like a permaculture forest would have, and they were doing well.  I don't think you should have too much to worry about.

A recommendation -- get some of the old-fashioned Gravenstein apples for your summer apples.  They don't keep very long -- have to be used up right away -- but at their peak they have no equal and the Pacific Northwest climate seems to suit them very well.  They also make the absolute best applesauce and apple butter.  You can use them for pies, but they mush up rather than staying firm.  There is a modern Gravenstein which is not at all the same apple; it may be a good apple in it's own right, but the one I'm talking about has stripes and is light colored, yellow and red, when it's ripe.  

Hi Kathleen, thanks for sharing that! Your grandmother's place sounds wonderful! What a great place to get to run around as a kid. I would love to have been able to find a property with an old orchard, but the home we finally found didn't have anything established besides the big hickory tree, which is beautiful, a couple of old walnuts that don't look so healthy, a few wild plum trees, and a pear tree that might have grown all on it's own.

I agree that old Gravenstein apples are great! My dad has had one for 20 years or so and it does make the best apple sauce - it's the striped one. I'd love to get a start from that one if I could... I haven't figured out how to do that yet. It produces regularly and never has issues with powdery mildew, or anything for that matter. I believe the powdery mildew in our area is only an issue for young trees, at least that's what I've read recently, so I'm only concerned about it while they are getting established. You might be right though, it might not be something I need to over-worry about. At our previous home we lost all of our apple trees and Asian pears to mildew and rust, but perhaps there was an infection in that particular neighborhood at that particular time. I hope that's the case, because fruit trees are expensive!

Thanks for the advice, I appreciate it!