This blog reviews the latest products, plants and innovations in gardening. It also provides a link for my many gardening friends who are members of the GardenMessenger and Seedmessenger Yahoo groups and their sub-groups that I moderate.

My Photo
Location: Australia

I am a semi-retired UK botanical garden curator and former international horticultural consultant, who has worked extensively in Europe, the Middle East, North America and Australia. I spend part of the year in Australia and part in Europe, mainly due to family and work commitments. I earn my living from writing and editing Internet copy, articles and books. I have written over fifty books on gardening and have been translated into twenty-four different languages. I am a former UK Garden Writer of the Year and a previous Quill & Trowel Award Winner from the Garden Writer’s Association of America. I am interested in developing gardening communities on the Internet and I manage the popular GardenMessenger Yahoo group, along with its various sub-groups like PondMessenger and SeedMessenger. I also edit International Water Gardener and its associated regional web-sites.

Saturday, April 22, 2006

Sweet Basil, Bearded Irises and New Clematis

Basil can be difficult

One of the great delights of summer are fresh salads. I love all salad vegetables, but especially tomatoes with a leaf or two of Sweet Basil. What a great plant, but what a problem it can be to grow, especially for gardeners who have cool conditions indoors, or who attempt to sow the seeds outdoors when the soil is still too cold and damp. Of all the herbs Sweet Basil is the most difficult to grow, and some gardeners give it up as a bad job and cultivate the very similar, much easier and small-leafed relative the Bush Basil. This tastes very similar to Sweet Basil, but has smaller leaves of a paler green.

The secret to growing Sweet Basil is a soil-based rather than soil-less compost, very careful watering and no feeding. If seeds are sown in a soil-based seed or potting compost and grown on by potting in the same medium they seem to prosper. Sow in a soil-less compost and they initially romp away, but almost inevitably produce blackened stems that have the characteristics of the common geranium Black Leg disease that I mentioned the other day in this blog. The stems produce black scarred tissue and almost always collapse. They certainly do not produce leafy productive plants. Soil-less and richly organic soils and compost are certainly not conducive to healthy growth. When pot grown, I also find that keeping the plants a bit tight in the pots also helps.


Bearded irises are amongst the most attractive frost-hardy plants for the mixed or herbaceous border. Give them a free-draining soil and plenty of sun and they are likely to prosper and flower. The greatest mistake that most gardeners make is in not dividing them regularly enough. I believe that they should be divided at least every third year if they are to give of their best. This was certainly the policy of the University Botanic Garden Cambridge in the UK where I studied in the early 1960s. They had at that time what I believe was one of the finest bearded iris collections in northern Europe, the nucleus having been provided by a private collector. The collection was so extensive, that it was actually arranged as an iris garden with beds, borders and broad grass walks. An absolute picture during June and early July.

Regular division immediately flowering was over, and only replanting vigorous young rhizomes certainly paid off. By dividing after flowering the plants had plenty of time to become established before winter, and most gave a good account of themselves, as regards flowering, the following season. In the second and third summers they were great. What the garden at Cambridge did was to divide one third of the irises each year to obtain the best of all worlds. So if you have six irises in your garden, lift and divide two at a time for each year for maximum floral benefit. Oh, and if you are looking for something new and exciting, just visit the French iris nursery Cayeux Iris click here.They have a wonderful selection and are launching ‘Réussite’ which means success, at the Chelsea Flower Show this year. This is a wonderful plant with tricoloured flowers that symbolise the French flag or tricolor. If you are interested in irises generally, why not join the GardenMessenger Iris Group click here.

Clematis ‘Lech Walesa’

There are several new clematis being introduced to home gardeners this year. One that is already exciting interest, and will be making its debut in the UK during the next couple of months is named for Lech Walesa, the former Polish president and leader of the Solidarity movement. Introduced by Thorncroft Clematis Nursery click here, it is an interesting pale blue flowered, mid-summer cultivar and apparently very prolific. Another one to watch out for is ‘Ice Blue’, one of the latest cultivars to be bred by Evison/Poulsen at Raymond Evison’s famous Guernsey Clematis Nursery in the Channel Islands. It is an early large flowered cultivar with very large spring flowers, some 15-20cm (6-8 in) in diameter. It is one of several new cultivars to be launched at the Chelsea Flower Show in May.

Clematis are great climbing plants for any garden where it does not get too hot. There is a rich assortment of cultivars, as well as some very good species, like Clematis tangutica, which not only has pretty yellow blossoms, but also very attractive silky seed heads. Of all climbing plants, it is clematis that present the most problems for the gardener when it comes to propagation. Some are quite easy to root from cuttings, but others are tiresome. While cuttings of many are a suitable route to success, if you only want one or two plants, then consider layering.

Layering is the process by which non-flowering stems of clematis and other plants are pegged to the ground, an incision having first been made in the stem to expose raw tissue so that roots can be initiated. In all other plants this is made close to a node or leaf joint in order that the greatest area of active cells that will induce rooting are exposed. With clematis it is always made between the nodes, for they rather perversely have a different cellular arrangement. The incision having been made and treated with a rooting compound, the stem is pegged down to the soil. Depending upon the species or cultivar, it may be a matter of weeks or months before it produces roots, but once the stem has rooted and has a life of its own it is detached from its "umbilical cord" and planted in its permanent position. I prefer to get a pot filled with good potting compost and plunge that in the ground next to the parent plant. The stem is then pegged into this, and once rooted can be removed as a pot-grown plant.

Happy Gardening.



Today’s Sponsor

Photos: Wikipedia, Cayeux Iris, Thorncroft Clematis Nursery.

To join the GardenMessenger gardening community
click here

To visit the SeedMessenger seed exchange web-site
click here


Blogger a-mini-gnome said...

Great bit about irises. Do you know what they symbolise?

8:19 pm  

Post a Comment

<< Home

Site Meter