Archive for April 2011

What to Do with Wood Ash from Woodstoves and Fireplaces

What to Do with Wood Ash from Woodstoves and Fireplaces

From one of my Per­ma­cul­ture Con­sul­ta­tion clients

Dear Cathe’,

It was great to vis­it with you yes­ter­day. I have a ques­tion. We have been col­lect­ing ash­es from Kath­leen’s fire­place in a large trash­can in the garage. I was won­der­ing about using them in the green­house or gar­den. Do you know of any uses for wood ash? What do you think about putting ash in the compost?

Love, Kather­ine

Hi, Kather­ine,

Take wood ash from wood stove or fire­place in a met­al buck­et. Nev­er store in plas­tic until ash is absolute­ly cool. This way you avoid burn­ing down buildings.

Use only high qual­i­ty wood ash. No ash­es from BBQ grills, card­board, ply­wood, paint­ed, or pres­sure treat­ed wood. Hard­wood ash (oak) is supe­ri­or to soft wood (pine) ash.

Three Caveats
1. DO NOT USE ASH IF YOUR SOIL HAS AN ALKALINE pH of 7.5 or high­er. It will make the soil too alka­line or salty. Alka­line soils are found in low rain­fall areas in the West. Use wood ash only in loca­tions where soils are acidic, like for­est soils and moun­tain soils, or places where there is ade­quate rain­fall in the warm sea­son .…not in alka­line soils like the desert. If in doubt, con­tact your local Mas­ter Gar­den­ers http://www.ahs.org/master_gardeners/

If you have been farm­ing or gar­den­ing with chem­i­cals, check your soil pH. Most chem­i­cals increase the pH and will even­tu­al­ly salt the soil

On the pH scale, 7 is neu­tral like pure water, below 7 is acidic with 1 being the most acidic like bat­tery acid; and above 7 is alka­line with 14 being the most alka­line like liq­uid drain clean­er. Nor­mal gar­den soil is typ­i­cal­ly 5.5 to 7.5 pH. Wood ash is typ­i­cal­ly 10.4 pH

2. Don’t use wood ash near these and oth­er acid lovers: aza­leas, rhodo­den­drons, blue­ber­ries, mums, marigolds, moun­tain lau­rel, oak, pecan, and sweet potato

pla 3. Sprin­kle wood ash before plants emerge, in win­ter or very ear­ly spring. Don’t plant seeds or seedlings until at least two weeks after ash has been applied, or wait until new plants are a few weeks old to spread it. The small­er they are, the more dra­mat­i­cal­ly plants may react to the sud­den increase in pH.

Wood ash has the same com­po­si­tion as lime­stone. Use it where you would use lime. If you put a pile of wood ash out­side, and it rains, it will turn to limestone.

The secret to using wood ash is to SPRINKLE IT or DUST IT.

Use wood ash­es to:

1. Spread fine­ly on the soil on your prop­er­ty. Use a large cof­fee can or a box with nail holes punched into the bot­tom. Spread so it looks like fine baby pow­der on the soil.

2. Enrich com­post. Enhance com­post nutri­ents by sprin­kling in a few ash­es so it looks like a fine pow­der. Adding too much, though, ruins compost.

3. Com­post­ing cit­rus rinds. In a buck­et of wood ash, place rinds of cit­rus or any­thing that is hard to break­down. Make sure to cov­er the bucket.

4. Cal­ci­um lov­ing plants. For cal­ci­um-lov­ing plants like toma­toes, sprin­kle and spread out ¼ to 1/8 cup (NOT MORE) right in the hole when plant­i­ng. More is not bet­ter. It should look like a pow­dered baby’s butt.

5. Block gar­den pests. Spread even­ly around gar­den beds, ash repels slugs and snails.

6. Con­trol pond algae. One table­spoon per 1,000 gal­lons adds enough potas­si­um to strength­en oth­er aquat­ic plants that com­pete with algae, slow­ing its growth.

7. De-skunk pets. A hand­ful rubbed on your dog’s coat neu­tral­izes that famil­iar lin­ger­ing odor.

8. Hide stains on paving. This Old House tech­ni­cal edi­tor Mark Pow­ers absorbs wet paint spat­ters on cement by sprin­kling ash direct­ly on the spot; it blends in with a scuff of his boot,

9. Clean glass fire­place doors. A damp sponge dipped in the dust scrubs away sooty residue.

10. Make soap. Soak­ing ash­es in water makes lye, which can be mixed with ani­mal fat and then boiled to pro­duce soap. Salt makes it hard­en as it cools.

11. Shine sil­ver. A paste of ash and water makes a non­tox­ic met­al polisher.

12. Kill moss in the lawn. Sprin­kle light­ly over lawns that have moss problems.

13. Tooth­paste. In the old days before tooth paste, ash was used to clean teeth. The poten­tial bio-haz­ards in the mod­ern world are the chem­i­cals used in fire starters, newsprint, and mag­a­zine inks. Using bak­ing soda instead tastes much bet­ter and is a com­mon practice.

14. Clean­ing white boards. Ash­es are good for clean­ing white boards that have been marked by grease pen­cil or mark­er. It even works on per­ma­nent mark­er that has been mis-applied to a white board.

15. Melt ice. My per­son­al all time favorite. Keep con­tain­er of ash­es in car (or on the porch for side­walks) in the icy sea­son to add trac­tion and de-ice with­out hurt­ing soil or con­crete under­neath. In Alas­ka, we car­ried a shoe box of fine screened ash to get vehi­cles out of ice. Sprin­kle hand­ful of ash­es out about a foot in front of the tires that have pow­er (4 wheel dri­ve ‑all tires; front wheel dri­ve ‑front tires; rear wheel dri­ve- rear tires). Dri­ve right out of trou­ble as if you were on dry pave­ment. Elim­i­nates the use of salt for icy sidewalks.

Check out the com­po­si­tion of ele­ments in wood ash, below, from the Uni­ver­si­ty of Georgia.

Hope this gives you some ideas for what to do with all that wood ash from our unusu­al­ly long and cold winter,

Cathe’

Com­po­si­tion of Ele­ments in Wood Ash Mean and (Range) tak­en from analy­sis of 37 ash samples

Macro ele­ments in aver­age %, range of 37 sam­ples, highest %

Cal­ci­um 15 (2.5–33) 31 Potas­si­um 2.6 (0.1–13) 0.13 Alu­minum 1.6 (0.5–3.2) 0.25 Mag­ne­sium 1.0 (0.1–2.5) 5.1 Iron 0.84 (0.2–2.1) 0.29 Phos­pho­rus 0.53 (0.1–1.4) 0.06 Man­ganese 0.41 (0–1.3) 0.05 Sodi­um 0.19 (0–0.54) 0.07 Nitro­gen 0.15 (0.02–0.77) 0.01

Micro ele­ments or Trace Min­er­als in mg, range of 37 samples

Arsenic 6 (3–10) Boron 123 (14–290) . Cad­mi­um 3 (0.2–26) 0.7 Chromi­um 57 (7–368) 6.0 Cop­per 70 (37–207) 10 Lead 65 (16–137) 55 Mer­cury 1.9 (0–5) . Molyb­de­num 19 (0–123) . Nick­el 20 (0–63) 20 Sele­ni­um 0.9 (0–11) . Zinc 233 (35–1250) 113

Oth­er Chem­i­cal Properties

CaCO3 Equiv­a­lent 43% (22–92%) 100% pH 10.4 (9–13.5) 9.9

% Total solids 75 (31–100) 100