How do I keep my soil dry enough to grow hardy kiwis?

My soil here is moist--a lot of my property is wetlands. Those portions that are not, are usually moist. Up until this weirdly dry spring/summer, I hadn't known what really dry soil was like!

I've been wanting to grow hardy kiwis, but I'm reading that they cannot have wet feet for more than three days in a row. I just don't know how to create such dry conditions in such a wet place. Does anyone have ideas?

I'm thinking of making a raised bed, and maybe placing some logs so that their faces stick out so that they act as a wick. But, would the wood hold too much water during the wet times of the year? Would a rock or cement edging be better? Digging ditches in the bed also seems like it might help, but I'm worried about erosion. Or, maybe I should just grow them in really big pots?

Hey Nicole
We face similar challenges with kiwi and lavender. What I've found works well is to mix our existing soil (clay based) 2/3s to 1/3 sand and hill it up almost 6" and plant dead center in the mound. I do not ever use any surrounds since they tend to harbor moisture. If my plants are on an incline, I will use the corner of a hoe to make a small swale, 2" deep to wick water away from their base. This has worked extremely well for me - hope it helps.
M.

I think a berm would work well, including a hugelkultur berm. Plants that don't like to be wet for days are plants that can't deal with the lack of oxygen that comes from being waterlogged. Hugelkultur beds hold water in the wood, but the soil surrounding it is not waterlogged. The water will wick out in the dry season, and be gathered up in the rotting wood in the wet season. Just physically having the kiwi vines' roots a couple feet off the ground is going to help quite a bit.

Chinampas are a good system for wet areas.

My sand is sandy/gravely loam (technically tokul soil http://em1202pacificnorthwest.blogspot.com/2013/03/soils-reveal-ancient-past.html, https://soilseries.sc.egov.usda.gov/OSD_Docs/T/TOKUL.html which is supposedly well-draining, but since it rains so much here, the water table is high and it's almost always wet.). So, if mound the soil high enough, I shouldn't need to amend it, right?

I'm thinking I'll have to raise it at least a foot, probably two feet. I've made 6 inch raised beds, and they have stayed moist enough to cause problems with zucchinis. But the top of my herb spiral and my three foot tall hugel stay pretty dry. If I put down a foot of wood and then two feet of dirt, I should be elevated enough to keep them dry...I hope!

What age/size of wood is best for wicking the moisture? I have a lot of one-year seasoned hemlock, as well as a BUNCH of red alder tress that fall in our woods and rot. The alders are pretty skinny--usually 4 to 12 inches in diameter.

Thanks for all your help!

Yes, you've just got to get things high enough over the water table that they aren't soggy for too long. With hugelkulture, it's a matter of "use what you've got." Sepp Holzer actually planted potatoes (with a plan to let them rot in place) in berms at a place in Montana when he ran out of wood, I guess to get some carbon into the soil.

Check out the chinampas idea, though - these are highly productive growing systems.

I have to confess that we didn't plan our kiwi planting at all. It was one of the first things we put in when we moved here, and I just had the general idea that I wanted a fruiting vine to climb around the porch rail and went for it. That said, I guess we lucked out because that placement means that it's downhill of the house and under the eave of the porch, which means the soil there stays relatively dry. Our female vine is on her third year and seems very lush and happy. We got her a boyfriend last fall, but our false spring was too much for him, being just recently planted. He used his energy to leaf out, lost all those leaves in a late frost, and just didn't have the oomph to give it another go. Same thing happened to the female, but she rebounded nicely.

Of course, not every house just happens to have a place for a vine with good light but protected from rain, but if you do have one it seems to work.

Julia Winter wrote:Check out the chinampas idea, though - these are highly productive growing systems.

I'm worried about it being too moist for too long. From what I'm understanding, they moisture evaporates out the top so only the roots are wet...but it rains so much here that there wouldn't be much evaporation. Also, according to Washington State Univeristy, they cannot stand more than three days of having wet roots. http://content.libraries.wsu.edu/index.php/utils/getfile/collection/cahnrs-arch/id/499/filename/96136182432004_pnw507.pdf Perhaps I don't really understand Chinampas, but wouldn't the roots be wet for more than three days?

Roberta Wilkinson wrote:I have to confess that we didn't plan our kiwi planting at all. It was one of the first things we put in when we moved here, and I just had the general idea that I wanted a fruiting vine to climb around the porch rail and went for it. That said, I guess we lucked out because that placement means that it's downhill of the house and under the eave of the porch, which means the soil there stays relatively dry. Our female vine is on her third year and seems very lush and happy. We got her a boyfriend last fall, but our false spring was too much for him, being just recently planted. He used his energy to leaf out, lost all those leaves in a late frost, and just didn't have the oomph to give it another go. Same thing happened to the female, but she rebounded nicely.

I wish I had a place like that! My house's roof does not overhang more than six inches . Thank you for talking about the frost damage and deaths. I'd been thinking about getting smaller plants because they are cheaper, but now I'm pretty sure I'll have to make the investment in getting a large plant to survive the frosts. We do live on a north-facing slope, so hopefully my lack of winter light will help them stay dormant longer and be more resistant to frost. There's got to be some advantage to a north-facing slope, right? Speaking of frosts, it might not have been just the age of your male that killed it, either. According to the Washington State University guide on kiwis, the males are less cold and frost tolerant than the females.

the males are less cold and frost tolerant than the females

Yes! A friend with many more years gardening experience than I told me that recently too. Not sure what to do about it. :/

I do think you're right that your northern exposure will keep them dormant longer and help with the spring frost problem. The same shelter that keeps the rain off creates a nice warm cozy pocket when we get those first tantalizing springy days in late March.

Sounds like you're on track with planting them in raised beds; we did this with the trio that we planted in the spring, we'll see how this soggy winter treats them...

Worth remembering that there are several different types of hardy kiwi; if you have shady, cooler areas with suitable soil/drainage, actinidia kolomikta may be a better fit the than the more common actinidia arguta.

I'd thought about growing actinidia kolomikta instead of arguta, until I read that they did not do well at all, growing sluggishly, being more sensitive to wet, and not bearing fruit (I print-screened the quote from http://content.libraries.wsu.edu/index.php/utils/getfile/collection/cahnrs-arch/id/499/filename/96136182432004_pnw507.pdf and attached it to this post because it would let me copy and paste). Since we're zone 7b here, I'm hoping we should be okay temperature-wise for the arguta. I think I'll be going with the arguta and crossing my fingers that it will do alright in a raised bed. Please keep me updated as to how your kiwi's do during this winter. As much as I love kiwis, I don't want to invest money in something that will just die!

On a kiwi belonging to one of my customers, I used split cedar boards like shingles,  to run some of the rain away from the base of the plant. When grown on a mound, it should be possible to run 90% or more of the water away from the roots during the winter.

 The boards are also an effective mulch. They reduce the amount of frost penetration. Remove them in the spring,  so that soil warming isn't slowed.

Interesting if disheartening link, Nicole; I'd heard similar things before, but not put quite as strongly. I hope to try a variety of the hardy kiwis, but trying Kolomikta first by accident of availability; I've got a 'Pasha' male, an 'Arctic Beauty' female, and an unnamed female that was being sold as an ornamental. Didn't do very much growing this summer, but no major dieback. I think the partial shade they have is less than they want, but I'm leaving them in situ another year to see what happens.

You may want to take a hoe out, after a good rain. It is often advantageous to not only raise areas, but to also provide a pathway for the water to move away. Anywhere that I find soggy or puddling, I simply use the corner of my hoe and make a tiny path, just like when I was a kid building forts with motes and waterways. It takes very little grooving to quickly remove water from any area. For us, with rains that come in long waves, I have to use mounding as well as channels to keep areas dry. Only take a couple minutes and the results are immediate.

I'm curious where the original 3 days of wetness reference came from. I generally feel statements like that are overblown. So on day 4 the plant dies? I live in CT the 9th wettest state and haven't seen any adverse affects of rain (currently in a drought).

I got the information about the three days of wetness from the WSU kiwi handbook. They said, "Research in New Zealand has shown that is roots are waterlogged for 3 days or more, the root system and vine growth are severely damaged." In the sentace before, they mentioned that the kiwi's were especially suseptible damage from water after budbreak. (https://www.healthyroads.com/Account/PasswordRecoverySecurityQuestion/?id=CLC25w43B4k3OCh25WBPvSXl4rYb1rncmxcL8dtP6Ono4DgBlul1zzRe%2fHykwW08, pages 6-7). So, the kiwis may be safe from excess water during their dormancy.

There's no reference section, however, so I can't find that "New Zealand research." I did note, though, that this handbook was written in 1998 (though this was revised in 2005, and they maintained this statement: https://catalog.extension.oregonstate.edu/sites/catalog.extension.oregonstate.edu/files/project/pdf/pnw507.pdf). So, while I'd love to see the New Zealand study, it was probably done before 1998, and thus not very likely to be easy to find through normal Internet searches (which I did try). Perhaps one could find it through library's collection of online journals, or perhaps by emailing Oregon State University, or Washington State University. I, however, do not have time for that--I'm just going to trust their word on it!

I'm glad I read this thread! I was planning on planting kiwi vines in an area that is pretty damp. I've had little luck with zucchini there, even in raised beds! Grapes prefer to be dryish too so I'm not sure what I'll plant there now! I might just have to create a taller raised bed!

I'm not sure I believe the can only tolerate 3 days of wet soil.

I live in the coastal rain forest of SE Alaska. We get a lot more rain here and more frequently throughout the summer than you do in Cascadia. Our soil never dries out, and I do mean never. Raised beds will occasionally dry out during a warm hot spell but regular in ground beds are always wet. I know of quite a few gardeners around town that have hardy kiwi. I've personally seen at least 2 that were planted directly in the ground with no particular cover or protection from the rain. I know those plants have to have wet roots for months at a time. Having said that one of the nicest/healthiest looking vines I've seen here is planted next to a potting shed where I does get at least some cover from the rain and wet. It is just planted right in the ground though and the surrounding path is covered in moss so that area has to stay pretty damp.

I bought two hardy kiwi two years ago and planted them in a raised bed. The female didn't survive the transplant but the male did ok. I transplanted it into a large pot early this spring while it was still dormant, intending to transplant it into a new area later. I also bought two more females. All three sat in their pots all summer (I didn't get the bed I had planed for them built). The male is in a large 10 gallon pot and the females in smaller (maybe 3 gallon pots). They all sat out on my exposed deck where they were rained on all summer and fall. We had a really wet June where is rained pretty much every day and rained quite a bit most days. I know the soil in those pots stayed wet for the whole month and probably the whole summer. I had to move some herbs I had next to them in similar pots because they were staying so water logged that the crowns started to rot. The kiwis were fine. They grew as few feet and had nice lush leaves. Maybe not the vigorous growth they could have had but by no means did they die. Considering they were pretty much ignored and never fertilized or provided any care that isn't surprising.

So I know that at least some kiwi can survive having pretty much constantly wet soil. Maybe they can't handle being flooded or total saturated soil but they will do just fine in damp soil.

Thank you, Chris, for sharing your experience. Fascinating! Do you happen to know if any of those hardy kiwis have produced fruit, or are the plants still too young? Maybe the wetness just impacts their fruiting?

Mine are still to young to fruit so I can't say personally. I've had several people tell me they do really well here, which is part of the reason I bought some for myself.

I do know that some of the kiwi around town do fruit. We were talking about them at a garden event and one member said hers fruits really well most years. Another person mentioned he gets fruit but usually just lets the birds and wildlife have it. Another had mentioned that she had a bumper crop this year. We had a warm, dry May followed by a wet cold June and July but lots of the berries around town did fantastic this year...the extra sun and warmth in May when lots of the fruit was setting seems to have made a difference. Might have contributed the the bumper kiwi crop as well. I do know that several folks were giving suggestions on recipes and examples of how they cook and/or preserve their kiwi. So based on that conversation there are at least a handful of kiwi plants around here that do produce decent crops most years and at least some years really good fruiting happens.

I couldn't say if the damp effects them. It might be that they would be even bigger with better fruit crops in a drier location. But they clearly can grow and fruit even in damp soil so I think they would be worth a try in your location. I wouldn't plant them in the wetland. But if you have a bit drier area and if they are in a raised bed with good soil that can drain I think they would do just fine for you.