By Debbie Oldfield
We have some really nice olive trees in the shop at the moment, so I thought I'd better remind everyone what versatile trees these are. Not only do they make a pretty, small, stand-alone tree with their nice silvery foliage, they hedge well, and they can also supply you with fruit to either pickle or make into oil… depending which variety you buy.
These graceful trees are wind, salt and frost-hardy and will grow almost anywhere in New Zealand. They are not that fussy about the soil they are to be grown in but prefer a well-prepared hole with lots of compost mixed in, especially if its heavy clay soil. Stake well.
Olives are very tolerant but do best in a sheltered position. Remember to keep up the watering so your olive does not dry out when the fruit is developing, and to apply annually some slow-release fertilizer. Olives can grow anything from 3-10m tall but can be kept to just 3m tall by pruning after harvesting the fruit. Size matters when it comes to deciding what variety you are going to grow. For pickling, large olives are a better choice. If you are going to press your olives for oil, size is not so important. How much oil they contain as a percentage is more important. You can still pickle 'oil' olives - all going well, they will taste great. Just understand they may be smaller, so there is less flesh relative to stone than with a larger pickling olive. Did you know one olive tree can provide up to 30kg of fruit?!
A lot of the olive varieties need to be pollinated with a different variety. Olives pollinate by wind from trees located within 20-30m so it is ideal to plant at least one other variety to help with pollination.
Here are a few of the varieties that are more commonly available:
Ascolano – If size matters, then this variety is perfect for you. The attractive very large fruit that ripen green, are great for pickling. Ascolano are fairly disease-resistant. Pollinate with other varieties, such as Frantoio and Leccino.
El Greco – El Greco is an attractive tree even if just grown for its silvery green foliage. It has a compact mature size of just 3mx3m, making it the perfect-sized tree for a smaller urban section. El Greco are self-fertile but are not known to fruit easily in New Zealand. This may be to your advantage as you don't end up with lots of very hard olive stones flying around when you mow under your tree. Good oil content.
Frantoio – This is a tidy and compact-sized tree at 4mx3m, with an early, heavy crop of medium- sized fruit. The oil from these olives has a peppery fresh-pressed taste and is great for using for dressings and dipping. They pickle well as an eating olive and are an all-round easy-to-grow variety. Very high in oil content.
Olives J2 – A very prolific producer bearing high yields of medium-sized fruit in autumn. A smaller growing olive tree with a willowy growth habit. Good for pickling. 4x3m.
Koroneiki – An attractive smaller growing olive tree bearing large crops of small fruit. Well-suited to coastal areas. Ideal for hedging and screening. Very high yields of high-quality oil or can be pickled. Hardy. 3-4m.
Leccino – Superb Tuscan oil selection that performs well in most parts of New Zealand. Healthy and vigorous, and tolerant of the cold once established. A medium-sized olive used for both pickling and oil. Very strong grower getting 5-7m tall, so may need more pruning. Pollinate with Frantoio. A good pollinator for other varieties. Early ripening.
Rakino – Olea Rakino is a shapely, small, open, tree suitable for both inland and coastal situations. A prolific summer fruiter, its flavoursome fruit is ideal for pickling. Suitable for warmer areas including Auckland/Northland. 3x3m.
Mission – A vigorous upright grower. Bears a heavy crop of smaller-sized olives which are best pickled. Grows well in the cooler regions. Self-fertile, 5m.
Carolea – Carolea olives are medium to large-sized olives grown both for oil and pickling. It has a good oil yield and small nut. The oil is considered to be a good-quality one. Will need a pollinator. 4x4m.
Verdale – French olive, good for pickling. It's a small grower used often for hedging and for screening, getting to around 4m tall. Self-fertile.