A Good Harvest

A few days ago I took a trip over to Stoke Newington in search of Ginkgo seeds. The Ginkgo tree is one that is very common, particularly in the middle of cities, because it is quite hardy and stands up well to the effects of atmospheric pollution. Unfortunately, it has on slight problem, its seeds, which have a distinctive, er, aroma that is a mixture of rancid butter and dog poo.

This means that female trees are something of a rarity and the male trees that are usually planted in cities are mostly clones of a small number of individuals. So, even though the tree is very common, it is actually an endangered species because so few trees grow from seed.

I haven’t counted them but I understand that there are 26 trees in one small corner of Stoke Newington, around the edge of a small council estate. Several of these are females, and they produce seed around November each year.

Ginkgo trees in Stoke Newington

I collected a sizeable jar full of seeds and found it strangely enjoyable carrying them home on the bus. I could see everyone looking around, trying to work out where the smell was coming from. Some even checked the bottoms of their shoes. After I got home, though, I found I’d got bits of the fruit stuck in my hair so the smell wouldn’t go away even though I’d left the seeds outside – serves me right, I suppose.

Freshly collected fruit


The seeds generally germinate quite well but they have to be prepared properly. First, the fleshy part of the fruit has to be washed off. This job is best done with gloves on, as the flesh reputedly causes dermatitis in some people (although I’ve never had any problem myself).

The seeds after cleaning


Once all the smelly goo has been washed off, the seeds have to be sanded to make the outer case more permeable to allow water to reach the seed inside. I’ve never been sure exactly how to do this, but I’ve always just rubbed away at one spot to make a small hole, hopefully without damaging the softer parts inside. After this, they need to be soaked in water overnight to allow them to absorb some water and soften a bit. Any seeds that are floating on the water after this aren’t viable, so a few were weeded out. I think I ended up with about 135 seeds, which should be plenty to produce a decent crop of seedlings in the spring.

Small holes made in the outer skin


After that, they have to be kept in a fridge for at least two months so that they know it’s winter. Some people say they should be packed in moss or sand, but I just put them in a bag last time and I had a pretty reasonable germination rate. Not having a fridge on the good ship Universe, I‘ll put this year’s crop in the gas locker although, given the current temperature on the boat, I think they’ll get the idea no matter where I leave them. Brrr!

I’ll post a progress report once they’ve started growing. In the meantime, there’s a mine of information about ginkgo trees at the Ginkgo Pages.