growing organic sweet potatoes
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Sweet Potatoeswww.strawberryhillfarm.ca
Growing Slips Heat to start sprouts on roots prior to
planting Plant only sprouted roots Do not cut roots – unlike potatoes which are
a tuber. Can remove slips over a 4 week time period Less stress at planting and more root =
faster take off Substantial cost and space required Risk of carrying over disease with
repeatedly using same stock
Buying Slips Much lower cost Plant all at once Slower establishment Less likely to carry on disease – no roots NC Growers are growing from TC and
virus indexing Faster planting Slightly less yield
General Information Will not grow below 60 degrees F Roots damage below 50 degrees F Day length sensitive
Require less than 13 hr. for root enlargement Early planting tends to promote sporadic
root development Ideal planting time for us is June 5-15
May planting less productiveJune 20 planting is getting too late
Site selection Full Sun from morning ‘til night Warm location Sandy loam soil
Don’t do as well in a clay loam Avoid early frosts in the fall Avoid wireworm or grub infested fields
Avoid fields that have been in sod for years Avoid deer habitat or prepare to fence Watch for mouse and rat damage
Soil Preparation Weeds – cultivate early season weeds Use deep cultivation to loosen soil Use bed shaper to make bed Cover with plastic layer Clear plastic works best for us if weeds
are not significant problem Try to cover a few days prior to planting to
heat the soil. May also be able to solarize weeds but needs to be hot for that to work
Planting 5’ wide bed center to bed center 30” bed top 2 rows staggered at 1.5’between (9” of bed)
gives best result1 X 12” row gives less per acre2 X 12” yields smaller tubers and similar to 1 rowBest for us = 2 X 18”
Hole about ¾ - 1” diameter is bestToo small = no room for shootsToo large = excessive weed growth and less heat
in bed
Picture taken June 16, 2014 bought slips
Planted June 11-12 – bought slipsPicture taken June 29, 2015
Picture taken July 1, 2013 our own slips
Picture taken July 8, 2013 own slips
Picture taken July 15 2013 our slips
Picture taken July 15, 2013 bought slips
Picture taken July 15, 2013 bought slips
Picture taken July 22, 2013 bought slips
Picture taken August 5, 2013 – Note deer fence
Picture taken August 5, 2013
Picture taken August 19, 2014
Picture taken August 16, 2015 double spaced at 18 inches (9” staggered)
Picture taken August 16, 2015 double spaced at 18 inches (9” staggered)
Weekly 9-2 to 9-24
4 plants 3.55 lb.
4 plants 6.05 lb.
4 plants 8.25 lb.
4 plants 8.7 lb
When to Harvest Soil temps are above 50 F, below 60 F Want to avoid frost damaging the tubers Very little growth after tops are damaged by
frostConsider covering for an early frost
Little evidence that covering other than for frost is helpful to get a better crop. Season long cover definitely not advantagousLast couple weeks might help – don’t know yet.
Picture taken September 17, 2012 Harvested with a fork – good yield lots of weeds…
Digger being used for regular potatoes
Picture taken September 25, 2015
October 6 2014
Curing & Storage Why Cure
Set the skinHeal woundsTurn starches to sugarsDramatically increase storage
5 days at 85 – 87 degrees F Up to 2 weeks if not quite so warm Store 55 – 60 degrees
Will damage below 50 degrees
Comparisons Tried brown IRT, green, black, white
biodegradable, and clear non-bio. About 30% increase from black to clear
plastic Some difference in yield between starting own
slips and buying, but not enough to offset other issues of time, space and heat cost
Numbers Yield ranges from 1-2 pounds per slip except
worst year 2013 was closer to ½ lb. Cost of production is about $0.53 per pound
in the warehouseLabour plus supplies, fert. and slips
Sold for $1.50-$2.00 per pound Gross harvest per acre ~ 18,000 lb. Gross sales per acre ~ $31,000
Varieties Beauregard – orange flesh
Best over many years growingOld variety
Covington – orange fleshGood variety similar to Beauregard
Orleans – orange fleshGood potential after 1st year 2015
Evangeline – bright orange, little lower yield Others with mixed results
Bonita, Japanese Yam, Satsumaimo, O’Henry, Carver, Georgia Jet