Dr. Kassab Holly

Holly bushes vary greatly, and some just seem to have a special ‘something’ that makes them stand out as very appealing plants in any garden. Perhaps it is the heavy crop of bright red berries, or the small, dark-green leaves with just a few spines. Perhaps it is the neat pyramidal form, with layering horizontal branches. Whatever it is, Dr. Kassab Holly, a hybrid form of the Chinese horned holly, is definitely one of those bushes with that special appeal. We love this tree, which forms a neat pyramid no more than 20 feet tall – another plus when so many holly bushes will grow to twice that size. Hybrid trees bring out the best features of their parents, and hide the weaknesses, and they have ‘hybrid vigor’ that makes them tough and reliable. This makes the Dr. Kassab Holly very resistant to heat and drought, alkaline soils, and the harsh conditions of hot, dry states.

Growing Dr. Kassab Holly

Size and Appearance

Dr. Kassab Holly is an upright evergreen shrub or small tree, with a dense, pyramidal crown. It retains its branches to the ground for many, many years, and the layered horizontal growth pattern of the branches gives it a very attractive look. It can be clipped to make a perfect formal shape, or left to grow in a more natural, but still dense, form. The leaves are just an inch or two long, glossy and leathery, and a dark blue-green color. They have a small soft spine at the tip and only four more – one at each corner of the leaf – making this plant relatively gentle and easy to handle compared to the English holly, with its many fierce spines. The leaves hold their color all year round, without yellowing, even on alkaline soils. Left to mature it will in time form a small, multi-stemmed tree, with smooth gray bark that is striking and attractive.

Clusters of small, greenish-yellow flowers form in spring along the stems of previous years, and these first turn into small green berries, and then by late fall they are bright red. The berry crop is very heavy, producing lots of berries for wreaths and vases, and they last well into winter on the tree, before they are taken by local birds. This female tree needs a male holly bush to pollinate it, to give you a big crop. We recommend any of our range of male trees, such as ‘Blue Prince’, ‘Jersey Knight’ or ‘Castle Wall’ as great trees to plant that will pollinate Dr. Kassab Holly as well as most other berry-carrying holly trees you might have.

Using Dr. Kassab Holly in Your Garden

This tree is perfect for a hedge as short as 6 feet, but it could also make a taller hedge to 12 feet or so. Plant bushes 3 feet apart, and trim as they grow, to develop a really dense structure. It is also beautiful planted on a lawn as a specimen. Try a group of 3 on a larger lawn for a lovely look, with the berries and glossy leaves catching the winter sunshine. It is small enough to use against blank walls in the foundation planting around your home. Plant it untrimmed as a screening plant, or among deciduous trees in a woodland garden. It is a great choice for a seaside location too, as it is salt tolerant.

Hardiness

Dr. Kassab Holly is hardy from zone 6 all the way through zone 9, and it is much more reliable in hot areas, both humid and dry, than the English holly.

Sun Exposure and Soil Conditions

Full sun or partial shade, such as the dappled shade beneath deciduous trees, is ideal for your Dr. Kassab Holly. It grows best in rich, deep and well-drained soils, and it tolerates alkaline soils well. It will grow in most ordinary garden conditions but avoid wet areas with poor drainage. Once established it tolerates dry conditions, and also ocean salt spray.

Maintenance and Pruning

This tree is generally free of any significant pests or diseases, and deer normally ignore it. If you are trimming it into a hedge or formal pyramid, trim in late spring once the new leaves have turned darker green. Trim again in late summer if you need to. Once it begins to flower, change your trimming to summer, once you can see the developing berries. That way you can avoid trimming too many of them off and preserve your winter display even on trimmed plants.

History and Origin of Dr. Kassab Holly

Dr. Kassab Holly is a hybrid plant, combining two species of holly. One is the Chinese horned holly, Ilex cornuta, which is a tree native to China and Korea. The other is Perny holly, Ilex pernyi, a small tree that grows in Gansu and Hubei Provinces in China. Dr. Joseph Kassab was a well-known and expert gardener who lived in Philadelphia in the years following World War II. He may have made this cross on purpose, or it may have been an accident, but in either case he noticed the value of this unique hybrid seedling and developed it into a very valuable garden holly. It has become known as ‘Doctor Kassab’.

Buying Dr. Kassab Holly at The Tree Center

Like us, many nurseries consider Dr. Kassab Holly to be one of the most useful and attractive holly bushes, yet it always seems to be in short supply. We have tracked down some top-quality plants, but they will not be on our farm for long, we know that. Order your trees now, while we can still satisfy your needs.