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Look Out......Winter is on the way

and other odds and ends

By Richard Douglas
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For the past several years, Northern California has escaped very low temperatures during our winter months of usual shorter daylight hours. The odds are good that sooner or later we will be hit with a “chilly blast” from the Gulf of Alaska, or even worse, a continental cold front such as we had in 1980/90. Many of us still shiver thinking of that terrible experience which was described by some as the "freeze of the century".

Forever pushing the limits, we palm nuts have been planting more and more "experimental" palms in our gardens. In the past few years many new palm species have become available, some of which are only questionable as to their hardiness to cold. We can speculate about the hardiness of these new palms depending on where they came from, but they haven't really been cold tested yet.

It is well known that Parajubaea cocoides, which has been in cultivation in Northern California for many years will take it down to 25 F. without damage, and it is thought that the newer species of Parajubaeas will tolerate much lower temperatures, but the true test will be when we get some real winter cold and frost.

In the past couple of years, I have planted in the ground, Arenga micrantha, Bismarkia nobilis, Parajubaea torallyi, Wallichia densiflora, and Caryota urens (hardy urens). The Bismarkia came through last winter without showing damage until warm weather arrived, and then it developed ugly splotches on the foliage. In March or April 2005 we had about a week of cool, misty weather with constant high humidity. Shortly after that, was when the damage showed on the Bismarkia. I tend to believe it was the dampness that caused the damage rather than the winter cold. Minimum temperature in Walnut Creek was approx 27 F. The Bismarkia resumed growth with warm weather and grew 5 new fronds this season.

This winter I plan to cold protect the Bismarkia, the Wallichia, and the Caryota. I plan to construct a frame over the palms and close it in with plastic sheeting, and maybe add a 100 watt light bulb to keep temps. from getting too low at night. The Wallichia and the Caryota are agonizingly slow for me, and it only takes one cold night or a week of cold to either damage or kill them.

If really cold weather is expected, (25 F. or below) I might throw an old sheet over the others to keep frost off the foliage. I realize that I'm really pushing it trying to grow a Caryota urens in my climate, but I had one growing in the ground for many years without protection until the '89/90' freeze. If I knew then what I know now....I would have a good sized Caryota had I planted one some years back.

Believe me, I'm not looking forward to a cold winter, but just in case, I will give some of my questionable palms some protection this winter. It's not worth the time and effort growing a plam for several years, then see it bite the dust just because of one or two cold nights.

Next spring, I plan to put Parajubaea sunki and microcarpa in the ground along with another Parajubaea torallyi, torallyi. Sooner or later, we shall find out just how much cold they can endure.

Things to look forward to. --.Patrick Shafers new cocosoid hybrids. They should be spectacular and hardy to cold. I planted one of Patrick's hybrids this past spring, a Butia X Parajubaea. It was a 5 gal size and never missed a beat in growth after it was planted. It has doubled in size this growing season and has grown 6 new fronds. This is a hybrid with great potential, but has not been cold tested. I plan not to cover it this winter. We are speculating it will withstand temperatures down to 20 or 22 F. without damage and probably survive much lower temperatures.

Good luck this winter, and don't forget to dig out some of those old sheets that are stuck away in a closet. They may save a marginal palm for you to enjoy another year, or many, in your garden.

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