I should probably explain why some species exhibit juvenile growth when young. Like citrus seedlings, many trees produce juvenile growth while small and within reach of grazing animals. Such growth may not be as efficient as adult growth, but is by some means objectionable to whatever vegetarian and terrestrial creatures would prefer the adult growth. When the trees are mature and beyond the reach of endemic grazers, more efficient adult growth emerges.

Examples include, but are not limited to, various species of eucalyptus, acacia, pine and (of course) citrus. Eucalyptus and acacia juvenile foliage avoids being eaten by being coarse and objectionably flavored. Wicked thorns protect juvenile citrus. There must be a reason for pine to produce juvenile growth, but I don't know what it is. Generally, such juvenile growth will not bloom or produce seed, because rapid ascension above grazers is the priority.

Ivy as a ground cover is juvenile growth that is not trying to avoid herbivorous predation but is trying to find a victim of its own. When it finds a supportive structure, such as a tree, it produces mediary growth, which grips and climbs. When it reaches the top of the supportive structure or is adequately exposed to sunlight, blooming and fruiting adult growth appears. Unfortunately, the adult growth easily overwhelms the growth of a tree that may be supporting it.

Creeping fig behaves similarly, but much more aggressively. In the wild, it is actually known as "strangler fig" because it actively constricts host trees as mediary growth expands. The once-climbing vines fuse and eventually become substantial enough to support the adult growth as the host tree dies and decays.

I should also explain certain classifications of citrus that I earlier neglected to mention. Contemporary cultivars of all types of citrus are divided into three groups distinguished by the acid and sugar content of their respective fruit: sweet, sour and bitter. For example, Valencia sweet orange is popular for juicing; Seville sour orange is used to make marmalade; and Chinotto bitter orange is an interesting ornamental that produces rather useless fruit.

Citrus growers often include the adjective that describes the flavor within the proper cultivar name, such as " 'Seville' sour orange." However, these adjectives may cause some confusion among everyone else who do not use them but might observe them on some labels. Generally, oranges and mandarin oranges not labeled as bitter or sour are sweet. Likewise, lemons and limes not labeled as bitter or sweet are likely sour. "Rangpur" lime is one of the few popular exceptions, as it is actually a sour mandarin orange.

Flower of the Week:
Parrot's beak

Parrot's beak, Lotus berthelotii, is certainly not common, but is a classic that has been enjoyed by garden enthusiasts for decades, particularly during the 1950s. The finely textured gray foliage on limber 2-foot-long stems must have been impressive as it cascaded out of those then popular and now dated slump-stone planters. The narrow, scarlet flowers are leguminous ("pea-shaped") and only an inch long. Bloom is typically during June. A very similar species, Lotus maculatus, is sometimes also called parrot's beak, but its floral color is generally yellow to orange-red.

Full sun exposure is preferred. Partial shade is easily tolerated but may inhibit bloom. Soil should be well drained. Established specimens require only minimal irrigation, but potted specimens should not get too dry. Winter frost may damage new growth.

Horticulturist Tony Tomeo can be contacted at 408.358.2574 or at LGHORTICULTURE@aol.com.