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Niger Seed is Guizotia abyssinica. This is an annual herb, which is noteworthy due to its oil-producing seeds. Apparently, it has been researched in the United States as a potential oil crop, but found to be of less promise than other oil seed crops already under cultivation.
Poison oak is native to most areas of California. It is an especially common inhabitant in the oak woodlands on the Central Coast. As people move into these areas, they can expect to encounter poison oak in their landscape and the surrounding vegetation.
Willows are fairly easy to propagate from woody cuttings, and I assume corkscrew will will work just as easily. Start by getting 3 or 4 one-foot long twigs from your friend's tree. The twigs should be at least a quarter inch in diameter and have several buds (nodes).
Research on pruning has changed our thinking about this activity. There are several times during the year when it is appropriate to prune. Traditionally, pruning of deciduous plants occurs when the plant is dormant or as dormant as possible.
Pruning trees will not speed up growth. In fact pruning off the lower limbs may actually slow the rate of growth. The growth rate of trees is dependent on the amount of leaf surface present and on genetic factors.
Several bits of information may have a bearing on the premature yellowing of the fronds. One, Queen Palms are native to Brazil (tropics). Thus, they are not well adapted to the Central Coast. However, they will grow here. Two, they require well drained soil.
The small, sparse foliage plus the excessive production of seeds suggest that the trees are under stress. Plants will often reproduce excessively when they are about to die. My references indicate that birch trees need well-drained soils with ample water at all times and a regular feeding program.
Most commercial roses are grafted. That means there are a rootstock and a scion to every plant. The rootstock is usually a rose that is very vigorous. Sometimes the rootstock will send up shoots from the base of the plant. These shoots are the suckers and they should be pruned off.
This may be caused by several factors: high soil salts chronic water stress high temperatures windy conditions high light exposure When excess soil salts are present and taken up by the plant, they accumulate at the leaf tip and leaf margins.
A number of years ago, researchers in Illinois (as I recall) placed a number of young trees in a greenhouse. One group was supported by (tied to) a stake. A second group was left to grow unstaked. And a third group was left unstaked but manually waved back and forth for several minutes every day.
