Good Morning -

I've asked the question administrator to forward your question about the kiwi to someone with that expertise.

But on to your compost question: I'm assuming that you're growing vegetables in containers filled with the Black Gold product. That's something Mt. Scott distributes, but they don't make it. And "Black Gold" is a product line, so I've not been able to get specific information about the average chemical analysis of the product. I notice that it's OMRI certified, so I'm confident that it undergoes a fair bit of analysis. When buying compost in bulk (not bagged, but a driveway full ...), you should expect the seller to be able to provide analysis.

Compost is not a homogeneous product, and so when put in a bag, we'd expect a certain variability from bag to bag or from batch to batch. Compost baggers would not put an N-P-K analysis on any product, because doing so is providing a guarantee. The inherent variability of compost prevents them from making such a guarantee.

Typically, I advise container gardeners to create their own mix of 1/4-1/3 compost to 2/3-3/4 potting mix. Planting in 100% compost could create salt problems which reduce the ability of plant roots to take up water. When I say "salt" I don't mean only sodium, but general chemical salts. However, the product you mention appears to include food waste in the mix, so no doubt there is some level of table salt present. It's not a problem until it's too much.

If I'm wrong about the containers, and you've amended garden bed soil with the compost, likely there won't be any need for additional fertilizing before the end of the summer.This is especially true if the garden beds have been routinely fertilized over the years.

As to pH - you could test that yourself an get a close enough reading with a test strip kit or pH meter. The test strips may degrade over time, depending on storage conditions. I'd recommend that you buy only from an established nursery with knowledgeable staff. Meters must be calibrated routinely to ensure accuracy. Either method requires that you follow the directions exactly.


Ideal soil pH for vegetable gardening is about 6.8 to 7.4. I definitely WOULD NOT amend container or garden soils with wood ash at this part of the season - the time for that would have been late March, early April.

Wood ash is highly soluble. It dissolves in water rapidly, and the calcium, phosphorus and potassium it contains are made available all at once. These, too, are chemical salts and could easily damage plant roots. I always recommend that gardeners applying wood ash test soils for pH annually. When testing for pH, it's best to collect the sample during the same 2-week period of the year, as soil pH varies on an annual cycle.

Wood ash does not acidify soil (lower the pH); rather it raises the pH. The end of the growing season is the best time of year to test soil pH. If you apply agricultural lime, it requires a great deal of time to react with soils. That's why commercial growers apply it in the fall.

That range of pH - 6.8 to 7.4 - should be good for any vegetable crop. Not blueberries, ferns, fuchsias.

Thanks for this very interesting question. I'm sorry not to have been able to give you direct answers to your complex questions. If you want to write back and clarify any points I may have gotten wrong, please do.

One more thought - there is a new pair of publications out from OSU Extension about soil testing. You'll find a link to the certifying agency for labs that test compost in the first one:

Get Actionable Results from a Soil, Plant or Environmental Testing Lab
Soil Testing Lab Selection and Recommended Analytical Methods for Oregon

Linda Brewer

Thank you. Linda. You give me a lot to digest. 

Hi and thanks for your question about growing Hayward Kiwi in Oregon. Oddly enough, we had the exact same experience with the male plant growing vigorously and the female not producing fruit and then finally dying. It turns out, Hayward kiwis are not winter hardy here, and I'm not sure there is any way to make them so. My son has a huge kiwi that produces fruit every year, but it is protected by a hedge which probably helps shield it from the coldest spring freezes. We, on the other hand, gave up and planted hops instead!

I'll attach an article about growing kiwi in Oregon which may give you some hints, but trying to grow this species, (Actinidia deliciosa) may just be a lesson in frustration.
https://extension.oregonstate.edu/catalog/pub/em-9322-growing-kiwifruit-your-home-garden

Hope you enjoy the hardy kiwi, which luckily likes our climate, winter and summer.

Thanks, Rhonda. Weird that male Haywards are SO hardy here, while females are so fragile. My current female survived the winter, but she's not growing, and in fact the leaves just shriveled up, and I think she's dying.

If you have the compost tested;

1. Choose a lab that provides an agronomic recommendation.
2. When you submit a sample, you will likely be asked what you're growing. The lab is not going to parse this out by specific vegetables. The lab's agronomist is going to give ONE recommendation for ALL the vegetables.
   

And back to the wood ash. Personally I never add anything to my compost that would change the pH. No, I would not put ash at the top of the heap and allow rainfall to distribute it. Doing that will not result in an even distribution. The first maybe foot of compost immediately under the place where you put the ash may well have levels of soluble chemical salts and pH high enough to kill the plants grown in it - even if it's mixed into soil.

Not all ash is the same. Its chemical composition varies with temperature of the fire, fuel burned, etc. And there is no affordable way to gauge just how much any given batch of ash will increase soil pH. That's why lime is so commonly used - over time, tests have been developed to allow an accurate prediction of soil pH in the spring after lime has been applied in the fall.

I imagine that you are a regular wood burner. Is it possible that you have ash and want to dispose of it? If so, the best thing to do is to be absolutely sure that no live coals remain, tie it securely into a plastic bag and put it in the trash.

I have a draft extension publication about the use of wood ash as a soil amendment in the home garden; my day job keeps getting in the way. It's research based - not my research, but published literature. But it won't allow you to know how much a cup or a 5-gallon bucket of ash will raise the pH of 100 sq ft of garden soil.

ljb

Hi, Rhonda.

John O:

Wood ash IS a traditional soil amendment that still has value. Think about it - everything we throw away goes into the soil or the water. And if we put it into the soil, it will go into the water.

It can be used safely and without causing harm, but allowing rainfall to carry an unknown amount of ash through a volume of compost sounds risky. The dose makes the  poison.

I've learned to be cautious when making recommendations in the public space because I can't tell how an unknown reader will interpret my  spoken or written information.

As to the potash from Terminal 5, sure, that has fertilizer value too. Current soil science thinking does not support fertilizer additions without analytic testing to determine the dose.

Your website is quite nice; you have a lot of content there. All publications in the OSU catalogue undergo a blind peer review, and there  is a team of staff in the publishing unit that ensure adherence to institutional branding and  marketing standards, reading level suitable to the audience, etc etc. At OSU, we are nothing if not bureaucratic.

ljb

Thank you for the explanation.