Germinating Parajubaea - Failures and Belated Success

By Mike Kenchington, Fordingbridge, Hants, U.K.
Chamaerops No. 51 - published online 22-04-2005

This is basically a tale of patience being finally rewarded. About 33 months ago, I purchased 50 seeds of Parajubaea cocoides. I bought so many because of their reputation for being difficult, nigh on impossible, to germinate. When the seeds arrived, I left half the quantity to dry, as put forward by many growers; the other half I sowed immediately. They were soaked for 24 hours in water, and then sown with the seed half buried in a 50/50 mix of perlite and vermiculite, and left at room temperature, around 18 to 21°C.

The ones left to dry were put in my greenhouse for two months. Temperatures in there fluctuate between 15°C and 35°C. These were then sown at the same temperature as used for the earlier batch, using the same sowing method after having soaked the seed for 24 hours in water. Then I waited. In the first six months, I had three germinate, one from the dried lot and 2 from those sown immediately. One of these subsequently rotted off; I think I might have planted it up too soon. Then nothing. Over the following 20 months or so, I tried every conceivable variation of temperature. Cold nights and hot days, cold all the time, and hot all the time, burning the seeds completely; I even tried a different sowing medium, all to no avail.
I have to admit I had given up any hope by now of germinating any more than the few original ones. At the beginning of last October I was rationalising seed boxes, trying to make some room, and came across the P. cocoides seeds. They had become very dry, so I soaked them in a liquid humate solution for 48 hours, then resowed them in my usual mix and left them at room temperature, around 20°C. On inspection after a couple of weeks, one had germinated, but no more. I decided then that I would chuck the remainder away after Christmas.

Early in December I had another look in the box and, to my utter amazement, found that 6 seeds had germinated. I just couldn't believe my eyes. This is being written on January 20th 2005, and to date l have a total of 25 germinated, including a couple of twin germinations. Now I don't know if it was the soaking in liquid humate or the seeds had just reached the correct stage of ripeness, but one thing is for sure, l will never throw away any seeds again unless they have rotted. I wonder how many viable seeds get thrown away because of impatience?