PART 3, THE 3-NEEDLE PINES OF AMERICA
In this series of blogs we are taking a deeper look at our native pine trees, both in the wild and in our gardens. In the first part we looked at how to identify pine trees, and then we looked at our native 5-needle pines. In this blog we will take a look at the diverse group of 3-needle pines that grow in North America. In the last and final part we will look at 2-needle pines.
American 3-needle Pines
As the name suggests, these trees all have 3 needles gathered in clusters and surrounded at the base with a permanent collar of papery fibers. These are therefore all ‘hard’ pines, unlike the ‘soft’ 5-needle pines that lose their collars, so the needles flop softly on the stem.
Not as cold-hardy as the soft pines, Pinus taeda, as this pine is called, is a tree of warm to hot areas, growing from Delaware to Florida and west into Texas. The name ‘loblobby’ comes from a Southern word for a mud-hole.
This tree is hardy only to zone 6, and unusual for growing well in wet, clay soils, while most pines prefer drier, sandy soils. It grows rapidly to around 100 feet tall, with a rounded crown. Exceptional trees can reach 150 feet. The needles are between 5 and 9 inches long, green and lasting on the tree for two years, falling in fall. This gives the tree a lush look for a pine, since most pines have needles that last just one year, falling in summer after the next year’s leaves form. The cones are 3 to 5 inches long and up to 2½ inches wide when open. Each cone scale has a sharp, ¼ inch spine on the end, forming a hook.
This tree is a fantastic choice if you like pines, but garden on heavy, badly-drained clay – conditions that are common in the southeast. It will also grow in ordinary soils, and once established it is drought resistant. Because it is fast-growing, it can be used for screening as well as decorative specimens, and it can be pruned, so you can keep it much lower and bushier than it would otherwise be. The only thing to remember when pruning pines is you cannot cut into wood where there are no needles. Bare branches will never sprout again. Always either remove a branch completely, or prune by removing just the few inches at the top. Ideal is to snap the new young shoots before the needles expand, called ‘candling’, leaving just an inch or two. Several buds will form for the next season, and this way a tree can be kept small indefinitely.
As the name suggests, this pine is easy to recognize, as the needles are up to 18 inches long – the longest of any 3-needle pine – although on younger trees they may be as short as 8 inches. The needles feel rough when stroked, and they are yellow-green, persisting for 2 years. This tree grows to 80 feet or more, but usually much smaller in gardens, between 20 and 50 feet. Cones are fat ovals, between 6 and 10 inches long, with a spine on the scales, and they sit directly on the stems, without a stalk. In winter this tree is especially easy to recognize, because the winter buds are 2 inches long and covered in shiny silver hairs – the trees appears decorated with candles.
Called Pinus palustris, which means ‘of swamps’, because this too is a pine that grows in wet areas, it also grows in gardens in ordinary soil, and is quite drought resistant. This is a tree for hot areas – only reliably hardy in zone 8, but probably fine in sheltered spots in zone 7. It was once an enormous forest from Virginia to Florida and west to Texas, but extensive logging has reduced that to only 3% of its original area. The logs were used for construction and flooring, and the tree was tapped for turpentine, which was used for fuel and paint-making.
As a garden tree Longleaf Pine is valued for the light shade it throws, and for keeping its lower branches well for many years. Once established it grows rapidly, so soon makes an attractive shade tree.
I have included this pine not because it has a wide range in America. It certainly doesn’t, coming from a tiny area in California and two islands in Mexico. But Pinus radiata is certainly the most widely planted pine in the world, because it grows very rapidly, and can be used for lumber and pulp for paper-making. The needles are bright green and no more than 6 inches long and the cones 3 to 6 inches long and egg-shaped, with a spine on the scales. Notice how that size difference in needles and cones is instantly a difference from Longleaf Pine, even though they both have 3 needles. Now you understand how to identify trees! It is grown extensively in plantations in Australia, Chile, New Zealand and Spain – it won’t grow in colder countries because it is only hardy to 5 degrees Fahrenheit. It will reach its full height of 100 feet within 40 years, and for plantations trees have been bred to grow with a single, straight trunk. It is also used ornamentally in California and similar climates, and considered a weed by many because it is so widely planted.
The Pitch Pine, Pinus rigida, is the only eastern 3-needle pine, so it’s very easy to identify when met in the wild. That is probably going to be on poor, sandy and acidic soils form Maine to Georgia and west to Kentucky. It’s an important part of the ecology of these ‘sand barrens’, providing shelter, nesting sites and food for many birds and small mammals. It has never been an important lumber tree – its too crooked – but it was used as a source of pitch, a kind of tar used for waterproofing lumber for mining, ship building and railway ties.
One of our larger pines – perhaps ‘ponderous’ best describes it – Pinus ponderosa can be found throughout the west, from British Columbia into Mexico. This is a large, pine, with a broad trunk, and wild trees can soar over 200 feet. Most in gardens and plantations are between 60 and 125 feet tall, with a conical crown of ascending branches, although the branches of older trees turn down. Young trees have gray-brown bark, but older trees develop striking – and easily recognizable – bark that is red-brown and divided into many plates with pronounced black cracks between them. The deep yellow-green needles are slightly twisted, and in tufts towards the ends of the twigs. Needles vary in length from 2 to 10 inches – botanist recognize 5 subspecies based largely on these differences – and they have a rough feel when pulled through the fingers. Cones are oval to egg-shaped, between 2 and 6 inches long, and usually growing singly, or occasionally in pairs. When open the scales show a pronounced spiraling.
Growing best in light soils, and very drought resistant, the Ponderosa Pine is a good choice to plant on sandy or gravel soils. It’s hardy to zone 4, so can be planted across most of the country, and will even grow beside the sea.