Tuesday, June 17, 2008

Vegetable Gardens and Woodchip Mulch

I broke a gardening taboo by using fresh from the trimmers truck, wood chip mulch in my vegetable garden. The conventional wisdom is that this will rob the soil of nitrogen and the plants will suffer. My twenty years of experience says otherwise and Dr. Linda Chalker-Scott, Associate Professor and Extension Urban Horticulturist at WSU Puyallup Research and Extension Center seems to agree, except in shallow rooted annual and vegetable beds. I routinely mulched bedding plants and all kinds of shallow rooted perennials with fresh wood chips and never had any problems.

For a client I would layer bagged compost or cow manure under the wood chips and add a light fertilizer application on top. In my own garden it was pure wood chips with no additions. The results were always exceptional.

Now I am not an extremist here. I want some produce from the roadside vegetable garden. I topped dressed each planting hole with some cow manure and did a very light, one quarter rate balanced fertilizer application.

Since it has warmed up, the vegetable plants are looking very nice.

The squash, melon and cucumber vines are beginning to vine. I have been warned of the dreaded Squash Vine Borer that is known to inhabit these parts. I don't want to do a preventative pesticide spray.

Instead I am doing a preventative root initiation along the stem procedure. If a stem borer should get into any of the vines a secondary root system may help them survive an attack.

The peppers have been the slowest to show signs of growth. They must like it hot. The crowns are full of flower buds and one pepper has even set. Still, they are looking not much bigger than when they were planted out. I don't think the problem is a lack of nitrogen.

What is going on under that mulch?

Expand the picture and you will see lots of small round pellets. The mulch has created the conditions for an on site fertilizer factory.

Free worm castings are piling up in the soil/mulch interface. Worm shit is good stuff!

And no that is not one of my crops. It was just a good link with info on the nitrogen content of worm poop that is being added to the soil on a regular basis that is readily available to the vegetables.

The tomatoes are looking good and have a nice deep green color.

Surrounded by fresh from the trimmers truck, wood chip mulch.

I hope they are all happy because the diagnosed low for tomorrow morning is now down to 45 degrees. Oh My! I already know they don't like the 40's.

Update 2010: The vegetable garden continues with wood chips as a mulch. Two years later, The Vegetable Garden in June 2010.

Refreshing the wood chips in 2010 begins.

Update 2011:
Creating A Vegetable Garden From A Pile Of Wood Chips


chuck b. said...

The gardeners at the Botanical Garden mulch everything with wood chips, like daily. Eucalyptus wood chips at that. The soil is amazing.

Christopher C. NC said...

I used Eucalyptus chips once, a bit worried about a possible allelopathic response and they didn't have any noticeable effect. The wood chips built my garden soil on Maui. Without them it would have been an ultra thin layer of dust with lots o' rocks.

Frances, said...

Good for the free wood chips, I was worried at first, but your stuff looks fine, great even. My pepper plants are tiny but bearing, we have picked jalepenos and sweet banana peppers so far. They do love the heat, we are heavy on that right now, but low of 45? Yikes!

chuck b. said...

I've lately heard that allelopathy turns out to be mostly bogus.

lisa said...

Lows in the 40's on June 17th?! We have more weather in common than I realized. LOL that link, but it's good to know the actual nitrogen content of worm castings. I plan to harvest a bunch from my worm bin this weekend, and my plants can't wait! (Yes, they told me so. No, I'm not drunk ;-)

Anonymous said...

Just reading about BRF (Bois rameaux fragmentés) in French.... a lot fo work has been done on the use of fresh woodchips as a soil improver in Quebec, France, Belgium and parts of Africa. I believe your approach of compensating for the early immobilisation of nitrogen is the right way to go & that you are going to build a great soil - you won't need fertilisers and in fact you might find you get better results without. Good luck... I am planning my BRF terrace garden for next year :)

Anonymous said...

Such good news - We got about 12 yards of wood chips last fall and now I can put all to good use!

Unknown said...

Thanks for dispelling the conventional wisdom on this - Ive just relocated to Australia and have mulched my garden with eucalyptus chips. Everybody is telling me that it will kill my veggies. My gut says they'll withstand whatever's in the wood.

Unknown said...

I've heard plenty about the nitrogen issue with wood chips, but I'm not sure I've ever seen proof. I'm happy to see that you've had success with this kind of mulch. I've tried many kinds, always avoiding wood chips, and it hasn't been working. I'm going to take the chance and try it out. Thanks for your help and for great, convincing pictures.

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