Hops Survive Hard FreezeBy
We had a hard freeze last night. I caught the temp on my outdoor thermometer as it was climbing, but it was 25 degrees fahrenheight when I took the picture. Sunday, Easter morning, my birdbath had almost a quarter inch of ice on the water so it has been subfreezing at least 2 days since the hops have sprouted and the weatherman says another freeze tonight. Good thing hops are hardy or they wouldn’t stand a chance here in Minnesota.
Established hops are hardy (can take freezes and survive). Newly planted hop plants or hop rhizomes sprouts are not as hardy. My friends and I have lost newly planted hops to freezes, the hop sprouts or hop bines die off and are never replaced – the rhizome dies off (I assume not enough stored energy to produce new sprouts). So be watchful of frost and freezing temps with newly planted hops. Just cover them up or wrap something around them to help capture and retain the heat from the ground. That is usually sufficient to protect them.
After the first year of growth, the rhizome will become a much larger crown or root stock and store much more energy to ride out freezes in subsequent years. I have been saying this but wanted to prove it with this post. Also you should have some mulch covering the ground around your sprouts/bines as an extra insulator. I use compost, leaves and grass clippings as a top dressing and insulator. Important – never use grass clippings from a lawn that has been treated with weed killer or even fertilizer as it can kill or stunt your hops growth.
From left to right: Nugget hops, Magnum hops and Cascade hops. The Nugget and Magnum hop bines are about 5 feet tall. The Cascade hop bines are trailing at about 4 and a half feet tall. As I write this the current temp is 42 and should easily reach sub-freezing temps tonight – I am not worried as experience tells me they will survive (again). It is supposed to start warming up after tonight (we are currently below average high and low temps for this time of year. I believe the hop bines are still on track to top out at 13 – 15 feet (15 feet at the peak of the garage – Magnum hops).
So there you have it, Don’t worry about freezing temps with established hops. Protect just planted hop plants and rhizomes from freezing temps until they are established – after 1 growing season.