It is time to start planting your cool season vegetable garden and also many flowering annuals, especially in drier regions of the island from Kohala to Ka‘u.
High food costs are a headache. Planting vegetables and flowers in yards and on lanai can help cut food costs. With the proper garden layout, you can create an attractive spot that will produce cut flowers as well as fresh vegetables. Both require regular fertilization and controlling insects and diseases, so they are a natural together.
In selecting the plot, remember that most annuals and vegetables must have six to eight hours of sun per day.
Choosing plants by height is one way to plan your garden. Some taller growing annuals for the back areas of the garden are cleome and sunflower. Some taller vegetables to try are Hawaiian super sweet corn, trellis tomatoes and Manoa wonder beans.
In the center rows and toward the front, consider medium height plants. Tuberose, blue salvia, tall ageratum, giant dahlias, red salvia and gypsophila are examples. Vegetables include peppers, squash and Waimanalo long eggplant. For low edging, you might use allysum, petunias, verbena, dwarf phlox or dwarf nasturtium. Waianae strain kai choi, won bok, Manoa lettuce and parsley are good varieties of vegetables.
Select a plot of good, well-drained soil near a water supply. It should be close to the home for convenience but should not be shaded by tall buildings or trees. Enclosing the garden spot with a fence is usually preferable, especially if you have feral chickens, pheasants, pigs or turkeys in the neighborhood.
Organic gardeners use natural and organic materials and methods for fertilization and pest control.
Organic fertilizer and soil conditioning materials are generally slow working and should be mixed into the soil at least three weeks ahead of planting. Clumps of inadequately decomposed materials interfere with the seeding operation and may result in nutrient deficiency and soil-borne disease problems.
Natural and organic materials that yield plant nutrients upon decomposition are available for purchase either separately or in combination. These materials may be applied to the garden separately or combined, used in the compost pile or mixed with manure.
Rock phosphates are natural deposits of phosphate in combination with calcium. When finely ground and with impurities removed, the powdery material is only slightly soluble in water, but may be beneficial to plants in subsequent seasons following application. A more readily available form of phosphorus is treble super phosphate.
Broadcast the material over the soil surface and work into the topsoil at least three weeks before planting. Manure or other organic fertilizer should be added at this time.
Potassium is widely distributed in nature. Wood ash, banana peels, seaweed, potash salts and ground rock potash are used alone, or in combination with other materials. Specific application rates must be determined for each material and its combination.
Organic materials contain many of the secondary or micronutrients plants need, in addition to nitrogen, phosphorus and potassium.
Reducing the acidity of the soil is the primary purpose for using lime in the garden. However, liming materials also provide nutrients for plants.
Calcium and magnesium are two elements provided by lime. Lime to sweeten the soil should be applied only when a need has been established by a reliable soil test. Apply lime two to three months before planting. Mix well with the soil and keep moist.
If you irrigate your garden, thoroughly wet the soil once a week, unless sufficient rain falls. This keeps soil moistened throughout the root zone.
Organic soil conditioners and fertilizers improve soil’s ability to retain moisture. Good garden mulch also conserves moisture and nutrients, reduces soil erosion and weed growth and provides a barrier between fruit and soil. It also moderates the soil temperature.
To reduce garden pests, plant pest-resistant varieties. Select pest-free transplants. Keep out weeds that harbor insects and diseases. Water in the morning and dispose of diseased plants before they contaminate others.
Many organic gardeners use sprays and other preparations containing naturally occurring materials such as neem. Pyrethrin, rotenone and nicotine are examples of natural poisons from plant parts. These give some control to some insects under certain conditions. Natural predators should be encouraged wherever possible. Some great books on vegetable gardening are available at local garden shops and nurseries.
The master gardener hot line offers information on vegetables suited to Hawaiian gardens. Call the University of Hawaii College of Tropical Agriculture Extension offices in Kainaliu, Hilo or Waimea for more information.