The Rostarara is known to be one of the toughest trunk-forming yuccas, Yucca rostrata is drought-tolerant and a popular garden attraction in the UK.
Beaked Yuccas are extremely tolerant to heat, drought, and frost. It can withstand temperatures as low as -14° degrees Fahrenheit. It offers a striking focal point in gravel gardens, Mediterranean gardens, and borders.
Yucca filifera is one of the largest and fast growing yuccas, it branches highly after about 3-4 m and can reach heights of 9 m with a trunk of 1.5 m wide. Y.filifera grows in northeastern Mexico. Y.filifera is stated to be cold resistant to around -8C but there are specimens around the UK that seem to have resisted much lower temperatures so it may be under rated if sited correctly. Kept dry and in a favourable sunny spot they can certainly take a few degrees more.
Yucca gloriosa (Spanish Dagger)
The most commonly seen outdoor Yucca that is probably the most proven in our damp climate. Over time they will produce a trunk becoming a Yucca tree and in summer produce a tall spike of creamy white flowers which is quite spectacular.
The sword shaped foliage is quite stiff and sharp so it should be grown close to where people or pets walk by. You also have to be careful when handling them, you can quite easily cut your hand or get poked in the eye by the tips of the foliage if you are not careful.
They can grow up to over 2 metres but not much taller so will suit most gardens. They are also very tough taking temperatures down to -15°C.
Yucca gloriosa ‘Variegata’
A variegated version where the leaf edges are a cream or yellowish colour that can turn pinkish red. Not as readily available as the standard green leaved Y. gloriosa. It is also just as hardy as the plain leaved variety.
Yucca gloriosa ‘Bright Star’
A variegated Yucca with more distinct variegation than Y. gloriosa variegata with brighter and more of a yellow colour to the edges. There are also finer variegation over the green central part of the sword like leaves.
Yucca Bright Star is a beautiful looking Yucca that is also very hardy here in the UK. A great alternative to Phormium for those who live in colder parts of the UK and find that their colourful Phormiums are getting cold and wind damage in winter.
Yucca filamentosa (Adam’s needle and thread)
Another hardy Yucca is Y. filamentosa taking temperatures down to -15°C, not all the varieties are this hardy so I am only going to mention the two Yucca filamentosa variants that are the hardiest and are available to buy in the UK.
If you want a more colourful variant then Color Guard has a bright yellow central stipe to its leaves. It is more or less identical to the green version just brighter. It is one of the hardiest variegated clumping Yuccas so ideal for the UK.
Yucca filamentosa ‘Bright Edge’
If you want a variegated Yucca with the variegation around the edges then Yucca Bright Edge has green leaves with a thin yellow margin around the edges. According to the RHS3 this variant is not as hardy with minimum temperatures down to -10°C although Havliz has this listed down to -29°C.
Blueish green sword shaped leaves and very similar in appearance to Yucca gloriosa except the foliage is softer, more curved hence one of the common names being Soft Leaved Yucca.
Y. recurvifolia is not commonly available in the UK but I think is such a good looking plant that its worth buying if you see it available. Hardiness is in the region of -15°C probably being its lowest temperature as specific numbers are hard to pin down.
Yucca recurvifolia ‘Monca’ aka ‘Banana Split’
A sport of Yucca recurvifolia and a bright and tropical looking one at that is Yucca recurvifolia ‘Monca’ also more commonly known as Yucca recurvifolia ‘Banana Split’ which pretty much sums up its appearance.
Again as with the green form of this soft leaved or curved leaf Yucca it is well worth seeking it out. Hardy, bright and tropical but able to easily withstand our UK climate. It can take temperatures down to -20°C.
Yucca aloifolia purpurea
As with most Yucca damp is the real enemy and a sunny spot will bring out the best in them. Purpurea benefits from direct sun as it enhances the purple colouring of the foliage. It will grow a trunk over time and look spectacular.
The leaves can be greener nearer the stem and the lower leaves if they do not get enough light. The mixture of green and purple does make this Yucca appear more visible in the garden. This can withstand -5oc possibly lower.
Standing majestically in their pots, these variegated garden yucca trees will make a beautifully architectural statement on any patio, deck or terrace - or you can also grow indoors as a houseplant.
They'll look good all year with their attractive spiky green and cream sword shaped foliage and bold structural outline.
They're tough, robust and drought tolerant for the summer months. They'll do best kept on the dry side in well drained soil in full sun, avoiding excessively wet conditions in winter, so if you have a sheltered spot, that will be best for them, although they also do well in exposed coastal locations. They may beed winter protection, as hardy to around -5oc