Yucca brevifolia 'Joshua Tree' Tonopah Form
Yucca brevifolia forma jaegeriana also known as the Joshua Tree has proven hardy in Colorado taking -22F several times and many negative teens. This is one of 3 forms that are grown by us, each exhibit very good cold hardiness. Keeping plants on the dry side in winter is key. Radical drainage helps with this as well. The seed for this was location was collected near the Tonopah Airport and is probably the furthest north location for this plant.
I do not guarantee these in a zone 5 because everyones growing conditions are different but this would be a good trial plant to grow in your cold outdoor garden. Try to plant outdoor 90 days before 1st hard freeze.
"Winter Dormant" Plants have been kept outside under an unheated greenhouse and can be shipped bare-root without heat packs as long as temperatures are above 10F in your area. Would still wait to plant in spring to adapt better to your garden.
Shipping: Packages can be held for a specific date. Please see our shipping section for information.