island bush poppy (Dendromecon harfordii)

Between the end of winter and the beginning of spring is an excellent time to appreciate the fleeting floral beauty of many ornamental trees and shrubs.
The mission of plants, like that of most living things, is simply to reproduce, and the best guarantor of healthy flowers, which are a plant’s reproductive organs, is moist soil.
That’s why you see most plants bloom at this time of year, before summer’s heat makes flowering, and every other botanical process, more of a burden.
February or March blooming is observed on nearly every California native. In this part of the world, it is vital that flowers are produced now so that pollination and seed development begin before desiccating heat is upon us. Just the other day, on Hauser Avenue between Pico and Olympic boulevards, I drove by the most glorious specimen of bush poppy I had ever seen. It was 6 feet tall, 4 feet wide, and its handsome gray foliage was covered with sunny yellow, symmetrical, four-petaled flowers. I had to stop the car, get out and examine this phenomenon more closely.
The bush poppy (Dendromecon rigida or Dendromecon harfordii) was growing against the stucco facade of an east-facing wall, capturing every drop of morning sun, and it was mulched underneath with small stones.
A stone, rock or gravel mulch is highly appropriate for every type of plant, whether native or imported, since it holds water in the soil and lengthens irrigation intervals. Small stones, such as the increasingly popular beach pebbles, come in a variety of natural colors. Gold-flecked gravel, sometimes called Palm Springs or Gold Rush, is also available. The advantage of a rock mulch, as opposed to bark or wood chips, is that it does not decompose and will only need replenishing where it endures foot traffic and may sink or scatter over time.
Bark and wood mulches must be reapplied every eight to 12 months. However, what is true of wood mulch is equally true of its rocky counterpart: it absolutely must be kept away from trunks or stems where they meet the ground. Otherwise, fungus will infiltrate between mulch and plant with potentially lethal effect.
Q.I have a garden where I plant tomatoes and peppers. It’s about 100 square feet in size with a big tree in the middle of it. The last couple of years my tomatoes aren’t doing too well. I get a lot of them but they all have big brown spots on the bottom of the tomatoes. What can I put in the soil to get rid of this problem?
– Bill Blachowski, Burbank
A. Heavy application of water or fertilizer, rather than a soil deficiency, may be responsible for your problem, which is brought on by lack of calcium in the fruit. The condition you describe, known as blossom end rot, is often caused by overwatering, especially when fruit is small and, although it is most commonly seen on tomato, may also occur on bell or chili peppers, eggplants and melons. In any plant, after water is taken up by roots, it heads straight for the leaves, from where it is distributed to stems and fruits. Along with the water, of course, come fertilizer and minerals such as calcium.
Abundant application of water or fertilizer means increased quantity and size of leaves. This excessive vegetative growth is highly demanding since water pulled into foliage is constantly being transpired or lost into the atmosphere through leaf pores. Fruits, on the other hand, do not transpire at the rate of leaves.
Since fruit does not pull water from leaves at the same rate leaves are pulling water and minerals from roots, calcium and other mineral deficits in the fruit may result.
Yet, too little water may also contribute to blossom end rot. If the flow of water and minerals to a young tomato plant is suddenly interrupted during a heat spell, for example, calcium transport to fruit will also be interrupted and blossom end rot will occur. The large tree in the middle of your vegetable plot raises the question of root competition for water and minerals, which could also contribute to your problem.
The bottom, blossom end of a tomato grows most rapidly and is especially needy of calcium when, only one-half inch in size, it begins to form its topmost, waxy layer of skin.
Calcium is a primary component of suberin, the waterproof, corky compound that gives texture to peels and skins of vegetables and fruits. That’s why it is so important to make sure that water, neither too much nor too little, which carries calcium along with it, is available to young tomato plants. The best way for assuring this steady moisture supply is to lay down a two to three inch layer of mulch on top of the soil that surrounds the plants.
You can grow tomatoes for many years in the same plot as long as you work a two-inch layer of well rotted compost, cow or horse manure, or Nitrohumus into the ground annually. Where calcium supply is concerned, annual application of gypsum or calcium sulfate to your tomato garden soil, as well as a pre-plant fertilizer that contains calcium, but no more than 5 percent nitrogen, is advised.
Tip of the week
Although bamboo is usually recommended as a screen because of its height, there are also dwarf bamboo species that are well suited as ground covers, especially for erosion control on slopes. You may see a stand of dwarf bamboo, along with tall bamboo types, growing in the Japanese garden located at the south end of Woodley Park, adjacent to the water reclamation facility, on Woodley Avenue just north of Burbank Boulevard. Although called dwarf bamboo (Pleioblastus and Sasa species), most types will reach 3 or 4 feet in height unless they are regularly cut back. Variegated cultivars are common. In order to thrive, dwarf bamboo will require two good soakings per week in hot weather.