Citrumelo, Hardy Grapefruit 'Dunstan'

I had a citrumelo tree that thrived for a few years here in Eastern Maryland (zone 7) but in 2014 the worst winter in decades killed it. ...Read MoreAfter that, with a little research I found the "Dunstan" variety and replaced the dead citrumelo with one the following summer. The small plant was only a few inches tall and wasn't planted until August. Due to space limitations it also is completely exposed to the west winds. With all that being said, it ended up being one of the coldest winters of all time a few months after I planted my new Dunstan. Despite not being established, it somehow survived the winter completely unprotected and ignored. This included one week with all lows under 10F for five consecutive nights, 4F on two nights, and no highs above 25F. The plant completely defoliated and died back to the mulch line. It showed no signs of life until May when some tiny and difficult to see leaves appeared near the base. It then showed basically no growth until July when it finally began to grow fairly rapidly, and now has replaced its original size (Late July 2015). Since winters like that are extremely rare, I expect it to grow to tree size after a few "normal" years.

I have never tasted a fruit, but many who have say its the best tasting trifoliate hybrid and has been described as like a grapefruit that just needs sugar. Some information says its a grapefruit and trifoliate hybrid anyway. They prefer full sun and protection from winter wind if possible, as well as good drainage since wet winters will really stress it.

The Dunstan has really impressed me with its cold tolerance, but these are very hard to find for sale, and you may have to order online to get one.

There are many hybrids made with the trifoliate orange (Citrus trifoliata L. (previously Poncirus trifoliata Raf.)) to try to gain its c...Read Moreold hardiness and other attributes as a rootstock.

The Citrumelo 'Dunstan' is hybrid of a grapefruit (Citrus paradisi) and the trifoliate orange (Citrus trifoliata L.)

The Citrumelo 'Swingle' is apparently a hybrid of the 'Duncan'
grapefruit (Citrus paradisi) and the trifoliate orange (Citrus trifoliata L.)