Gardeners and farmers are kin, and I’ve found myself listening incessantly to a particular podcast where one farmer, Chris Blanchard, interviews other farmers. The Farmer to Farmer podcast has given this gardener wheelbarrows of food for thought.
Some of my favorite episodes are the ones with:
Nigel Walker of Eatwell Farm, from whom I gained a deeper appreciation for soil,
Jim Gerritsen of Wood Prairie Family Farm, from whom I learned a whole new universe worth of insight on potatoes,
Bob Cannard, who challenged me to reassess my relationship with weeds,
and Karl Hammer of Vermont Compost Company, who would be entertaining enough to listen to even if I didn’t care about compost. But maybe the most fascinating thing I heard in the interview was that he raises hundreds of laying hens that live solely off of his mountains of compost.
I just watched the Amazing Race, where they traveled through Peru, and it reminded me of how much I like to grow potatoes. Compared to potatoes, most other staples can be laborious to get from the ground to your dinner plate. Wheat, for example, takes a lot of work to dry and thresh and grind into flour unless you have machinery. Potatoes, on the other hand, can nearly grow without you paying attention, and harvesting them is fun like digging for treasure.
What follows are my personal notes on what I’ve learned about when and how to grow potatoes.
For this yard, in Southern California, the best planting time is February. I think of potatoes as having two seasons here — one is August to a Thanksgiving harvest, and the other is February to a late spring harvest. While I’ve gotten good crops out of planting in August, I’ve gotten consistently better crops from February, for a couple reasons.
Yukon Golds planted in February 2015 and harvested late May
Growing from February takes advantage of the rainy season, so less watering is necessary. February planting also requires less attention to the plants generally. For example, my last August crop suffered from spider mites because I used drip irrigation and there was no rain to wash the foliage off and I failed to bring the hose out to give the plants a shower frequently (mites infest dry, dusty foliage). The only disadvantage in my yard of growing potatoes in February is that the earwig population tends to explode around April, and they munch the potato plant leaves. But yields don’t seem to suffer since the plants are big enough by then to cope with it.
Many sources claim it’s vital to use seed potatoes that are certified disease-free, but for so long I’ve grown some of those alongside seed potatoes that I bought from the grocery store that were intended to be eaten, as well as seed potatoes taken from a previous harvest of my own. And I’ve never noticed a significant difference in plant performance, disease, or tuber yield.
I’ve also found the claim of needing to chit, or pre-sprout, the eyes on the seed potatoes overemphasized. When I plant a seed potato with eyes a half-inch long compared to a seed potato with eyes that haven’t sprouted, they both grow well. The seed potato with half-inch eyes just emerges faster, that’s all.
I’ve had good results planting potatoes in August right at the base of recently harvested corn — the corn having been sown in the spring. Potatoes seem to like following corn.
When planting, you only need to bury the seed potatoes in a furrow about three inches deep — no deeper. I used to dig furrows deeper, but it never improved yields and it only made me dig deeper to harvest the potatoes.
Until plants emerge, the soil around the seed potatoes only needs to be slightly moist. In other words, don’t keep it saturated. I’ve made that mistake in the past and rotted the seed potatoes.
Over the course of the plants’ three to four months of life, I usually heap up dirt on them twice — once when the plants are around six inches tall, when I fill in the furrow, and then again when the plants are another six inches above the regular level of the soil surface so that ultimately there’s a mound of dirt about three inches high around the base of each potato plant. If I see a tuber showing at the base of a plant I’ll throw some extra dirt over it.
These days I use in-line drip emitter tubing where the emitters put out 0.5 gallons per hour and are spaced one foot apart. I plant each seed potato one foot apart so there’s one emitter per plant. At first, I wasn’t sure this would saturate a big enough area in my sandy loam soil, but it has been working just fine. Once the plants are about a foot tall, I give them approximately as much as my local ET rate.
At the beginning of each of my drip tube lines I have a shut-off valve so I can quit watering the whole row of potatoes once the plants are full sized and starting to yellow.
Harvesting is easier when you can dry out the soil around the potatoes for at least a week or two prior. The tubers then pop out of the dirt very cleanly — no cakey mud on them that needs to be scrubbed off.
In mid-December, 2015, the foliage of my potato plants were damaged by frost, but I waited to harvest until December 29. The tubers were all perfect, as if they were just being stored in the soil. The lesson is that you need to get the plants going by August so they mature and develop tubers before a December frost, yet you don’t have to harvest them immediately after that December frost. They’ll wait safely in the ground.