Image provided by: University of Oregon Libraries; Eugene, OR
About Vernonia's voice. (Vernonia, OR) 2007-current | View Entire Issue (Nov. 21, 2019)
8 in other words november 21 2019 Diggin’ in The Dirt: Planting Over Septic Fields By Chip Bubl Oregon State Extension Service Columbia County Master Gardener™ class sign-ups being taken for 2020 class in St. Helens The OSU Extension office in Columbia County will be offering the Master Gardener™ training again this spring. This year, we are trying a new schedule that allows people that work to attend. The classes will be held on Wednesdays from 6 - 9 pm and on al- ternate Saturdays from 9 am - 4 pm for about 10 weeks starting on February 5, 2020 at the Extension office in St. Hel- ens. Cost of the program is $100 which includes a large resource book. Some scholarships are available. Master Gar- deners are responsible for providing vol- unteer gardening education to the com- munity as partial payback for the train- ing. If interested in the program, call the Extension office at (503) 397-3462 for an information packet. Online registra- tion is now available at https://tinyurl. com/ColumbiaMG2020. We can also send you an application and/or you can come into our office to sign up. Planting over septic fields A recent review of articles about planting on a septic drain field offer a range of opinions about what, if any- thing, is suitable. The concerns seem to be focused on three areas: that com- paction of the soil over the drain fields by gardening activities may lead to a reduced life for the field; that root en- croachment into drain lines can lead to their failure; and the risk that septic ef- fluent might contaminate fruits or veg- etables grown over a septic field with human pathogens. A septic drain line is engineered to function with the natural soil drainage and rainfall to decontaminate the effluent. Adequate aeration is crucial to make the system work. Often, lines are covered with gravel/sand at in- stallation to improve aeration. There is a concern that adding soil (as in raised beds) over the septic lines can upset the oxygen flow into the drain lines. I am not sure how valid that is. However, ro- totilling, livestock grazing, and/or walk- ing or routinely driving anything over the drain field area when the soil is wet will compact it. That will restrict oxy- gen penetration and lead to a degraded system. While the impact of those activi- ties may not be immediately seen, there is good evidence that it may shorten the life of the field from 40+ years to some- thing less. However, data is sparse on this topic Other writers take the position that it is possible to grow something be- sides grass as long as the beds are not compacted by the activity. The most common materials recommended are herbaceous perennial flowers, ornamen- tal grasses, ground covers, and shallow rooted shrubs like lavender, azaleas, rhododendrons, and blueberries. Annual mulching to keep the soil surface loose and the weeds down should keep the aeration in good condition. One writer suggested making the surface of the actual drain lines into paths covered with gravel mulch and growing plants in the space in between. I’m not sure that is a good idea. There is general agreement that deep-rooted trees should be avoided. There is plenty of evidence that some tree roots will invade drain lines and can plug them up. Cotton- woods and willows have a fairly bad reputa- tion in this regard, but I can’t imag- ine many trees passing on the opportunity for the nutrient filled drink that the drains lines provide. Since effective. There also is agreement that if you decide to grow vegetables over the drain line, plant only those whose ed- ible portion is held up off of the ground. There is no evidence of disease trans- mission from septic effluent through roots and systemically into a plant. The concern is that human pathogens in sep- tic effluent might attach to the surface of the edible portion of a plant, especially if that edible portion is in the soil like an onion, carrot, or beet. Leafy greens are at risk from rain splash of septic con- taminated surface water. Safe choices include corn, and trellised crops like to- matoes, beans, peas and cucumbers. If your system is failing (a good sign is a rotten egg smell) it is important to get a new drain line put in as soon as possible. Lime for lawns and gardens Limestone is a mineral widely used in farming. Limestone, which is ei- ther straight calcium carbonate or a mix of calcium and magnesium carbonate (dolomite), is mined and then ground to a fine consistency. Lime works wonders when tilled into soils. First, it provides calcium and magnesium which are de- ficient in Columbia County soils. Second, as lime reacts with the soil chemistry, it makes the soil less acid. We say it rais- es the pH of the soil. Most plants prefer a near neutral pH of 6.5-7. Our soils often test at fruit soils. Most berries like lime, though at a slightly lower rate except blueber- ries which prefer very acid conditions and should not be limed. Lawns should have about 100 pounds per 1,000 square feet applied as a more finely ground “prilled” product (one trade name is Cal- pril). Flower and shrub beds will do fine with about 75 pounds per 1,000 square feet but again, don’t fertilize acid loving shrubs like rhododendrons and azaleas. Free newsletter (what a deal!) The Or- egon State University Extension office in Columbia County publishes a month- ly newsletter on gardening and farming topics (called Country Living) written/ edited by yours truly. All you need to do is ask for it and it will be mailed or emailed to you. Call (503) 397-3462 to be put on the list. Alternatively, you can find it on the web at http://extension. oregonstate.edu/columbia/ and click on newsletters. Take excess produce to the food bank, senior centers, or community meals programs. Cash donations to buy food are also greatly appreciated. The Extension Service offers its programs and materials equally to all people. Contact information for the Extension office Oregon State University Extension Service – Columbia many of our trees have roots that extend as much as 30% beyond the width of the mature crown, careful location of land- scape trees is very important. There are root barrier fabrics that can be installed to keep tree roots from the lines but of- ten those are best put in when the drain field is installed. They also aren’t 100% a pH of 5.5-6. As the soil becomes less acid, the plant is better able to extract important plant nutrients like phospho- rus and potassium. Most vegetable garden soils can benefit from about 125 pounds of lime per 1,000 square feet of garden once ev- ery three years. The same goes for tree Where Do You Read The Voice? Show us where you have traveled. Submit your photo with a brief description by email to: Scott@VernoniasVoice.com. County 505 N. Columbia River Highway (across from the Legacy clinic) St. Helens, OR 97051 (503) 397-3462 Email: chip.bubl@oregonstate.edu Vernonia’s Voice is published twice each month on the 1 st and 3 rd Thursday. Look for our next issue on December 5. Don’t Sell it! Pawn it! For fast cash! • Kitchen & Bathroom Remodels • Finish Carpentry • Ceramic Tile Work • Custom Home Construction • Additions • Commercial Tenant Improvements Baseline Pawn, Inc. 2245 Baseline St., Cornelius (Across from Fred Meyer) 503-530-8119 State Licensed PB-0388 Open everyday at 10 a.m. Jim Morrison, Jr. General Contractor CCB# 112057 Ph: (503) 429-0154 MorrisonRemodeling@hughes.net Vernonia, OR 97064 • Licensed • Bonded • Insured Fresh Roasted Coffee espresso • baked goods Open Every Day at 6:00 am 825 Bridge Street 503-429-0214