Short Season Cassava

We work with introducing culturally relevant varieties to Iowa to support our growing community. I get a lot of requests for cassava which we are in Zone 5 (the growing season for warm crops is June-early October), so typically cassava is not an option. However, I was reading about short-season purple cassava in Bolivia that was under 120 days for tuber maturity. With a greenhouse jump start and tunnels, I wonder if we could eek it out in our zone.

But I can’t find stocks anywhere to buy. Does anyone have a recommendation or experience growing it in colder climates?

Thank you!

There have been numerous successful attempts to grow tropical plants in temperate climates (greenhouses, tunnels, geothermal heating, solar heating, compost heating etc). The question always is whether the (financial) effort is worth it, whether it is sustainable/climate friendly and whether it isn’t easier to stick with plants that fit into the climate zone.

This person has done it in zone 6a, but for leave production only:

I grew up on a Iowa farm and worked with the USDA Risk Management Agency focused on Iowa agriculture for much of my professional career. In the northern third of Iowa it wasn’t advisable to plant corn with maturity times beyond 100 days. Greenhouses and/or tunnels certainly will extend the growing season. However, are there enough “growing degree days” (seasonal heat unit accumulation) for semi-tropical/tropical crops such as cassava? Before investing in a greenhouse it may be worthwhile to survey the community for culturally acceptable alternatives that readily grow well in temperate climates.

Thanks for the reply. We have tried several alternatives over the past few years without acceptance (burdock, different sweet potatoes, root veggies). The leaves are also highly valued. With our growing refugee population, this is one of the major tasks and we’re exploring if there is any way we can improve access to it here. We have grown pilots successfully in heated greenhouses, but it’s not worth the cost on the scale.

It’s good to know alternatives have been suggested but not accepted. Many other stories of non-acceptance exist as well as “that’s the way we’ve always done it”. Other than promotion by trusted members within the community I don’t know how to get past that barrier. So, the focus of your inquiry gets back to an affordable season extending structure for Iowa’s temperate climate scaled to a growing communities needs. Have you contacted a garden specialist with the Iowa State University Extension Service? I will bring up your inquiry at the ECHO tech response meeting.

Hey @Micah_Dettweiler do you know of any varieties Emmaly might want to look into?

I’ve been growing cassava in Zone 9a and that’s still a little colder than ideal; besides the risk of cassava dying when it freezes, it also seems to grow pretty slowly in cool weather. On the other hand, a 4-month growing season is enough for cultivating cassava leaves, especially with a greenhouse start.

That 120-day purple cassava variety sounds pretty great; most early-maturing cassava varieties I’ve heard of still take 7 months to grow. Unfortunately, I think getting specific cassava varieties in the US is pretty difficult (especially in bulk) because stem cuttings are large and perishable and there are more regulations on shipping stem cuttings than there are for shipping seeds.

I’m glad to hear that cassava is in high demand, and I’m sure cassava leaves are possible in Iowa even if roots take too long!