Rhodies, handkerchiefs and candelabra

A quick paean to the glories of Kenwood in May – the rhodedendrons and azaleas and the handkerchief tree.

The big lawn to the west of Kenwood House is entirely surrounded by mature camellias, magnolias, rhodedendrons and azaleas – so in April and May it is a delight to behold. Apart from the surrounding  trees there are also two very large beds actually in the middle of the lawn which were also filled with mature rhodendrons and some azaleas which. Over the years these had grown to 10-15 metres in height and were in serious need of a major trim. I understand that the gardeners had planned a fairly sensitive programme of pruning over several years which would have reduced them without damaging them too much. But then a decision was taken on high and the guys with the chain saws arrrived. The result was two large beds of stumps surrounded by vigorously growing weeds delighted to have finally escaped from under the rhodendenron bushes.

As you might imagine, this caused a great deal of unhappiness among Kenwood devotees but at that point the deed had been done. This all happened about four years ago and, as you can see, some of the bushes have recovered reasonably well – but many are struggling and quite a few failed to make it at all. (The weeds, however, are flourshing!) None the less, the bushes that have made it and are now in flower are still truly magnificent.

Meanwhile, the Handkerchief tree at the south western corner of the lawns at the end of the lime avenue is also in full flower – although technically it does not produce flowers but large white bracts which look exactly like freshly laundered white handkerchiefs waving gently in the breeze.

I got very over excited last year about the handkerchief tree (first brought from China in the late 19th century). I felt it was being totally underappreciated because it was being smothered by the end trees in the lime avenue. But I had to eat my words when I discovered that the UK’s leading expert on handerchief trees had said that it owed its size and health to the fact that it was protected from the buffeting winds by the surrounding limes. (To learn more about how it made its perilous jurned to England see my post in June  last year.)

Even though the handkerchiefs are the most striking thing about the trees, the tiny pruple flowers which sit at the heart of their handerchiefs are also very pretty.

Not actually on the Kenwood estate but very close by – running in fact along the border between the heath and the grounds of Athlone  House – is a magnificent line of horse chestnuts. Somehow this year I managed to miss that amazing sticky bud time but I did catch them with their candelabras fully alight.

Did you know – well, probably lots of you did, but I didn’t – that the flowers change colour once their pollen has been taken?

Once the pollen is taken the centre of the flower changes from yellow to pink so that cruising insects know not to waste their time on blossoms that have had their p0llen taken and focus their efforts on the still pollen laden ones.

But, however beautiful they may look, horsechestnuts are not great for those with allergies. Below is a comment to an earlier post from Tom Ogren, our world expert on flower and plant allergies. (For more on Tom’s work see his site, Allergy Free Gardening, buy some of his books and/or check out this section of the FoodsMatter site where you will find lots of articles and videos about allergen free gardening.)

Per the horse chestnuts and allergies:

Their flowering systems are a bit more complicated than most. Yes, they do make many perfect flowers (flowers with both male and female parts in the same flower), however, they also make numerous other flowers that are all-male (and therefore potentially allergenic). This flowering system would be called polyandros. Those all male flowers are less showy, and they all will shed plenty of pollen.

Here is something I published on this in 2004, in the book, Safe Sex in the Garden:

Polygamous flowering plants will have both perfect-flowered flowers and single-sexed flowers on the same plant. A buckeye tree (an American relative of the horsechestnut) is a good example of polygamous flowering. The buckeye in bloom will have great clusters of flowers on the ends of each branch. Often these clusters will be a foot or more in length.

On the tips of the flowering branches all the blooms are perfect-flowers, each individual flower complete with fertile female and male sex organs. However, six inches or so above the tips of the branch there will be many unisexual (one-sex) flowers, and with buckeye these will always be male-only flowers. The clusters of buckeye flowers are Nature-designed to be pollinated by both insect and the wind, and as a result pollen from the male-only flowers indeed can become airborne and cause allergy.

Another note about the horse chestnut trees, bee keepers don’t like them because often the pollen is deadly to bees. On occasion bees working them will produce poisonous honey.

They are handsome though….just don’t plant one too close to your house!