|I'm new to the area and have a question about fertilizing oleander and Texas sage. Do these shrubs require acidic soil?|
|Texas sage (also called Texas ranger or Leucophyllum) will grow in a wide range of soils. It's native to alkaline soils of Texas and Mexico. Oleander tolerates incredibly poor soil, including dry, rocky alkaline soils of the Southwest. (That's why you see it used in so many inhospitable places, such as freeway medians.) So, no, neither of these plants are acid-loving.
Since you said you are new to the area, note that all parts of oleander are poisonous, and can cause severe skin
irritation in some people. Once established it's exceedingly hard to remove.
Desert-adapted landscape shrubs usually don't need much in the way of fertilizer. If you mulch with a 2-3 inch layer of compost around the plant, it will break down and provide nutrients slowly over time.
If you determine that fertilizer is necessary, choose a fertilizer high in nitrogen. You can use a soluble fertilizer, such as 10-10-10, or an organic fertilizer such as blood meal or fish emulsion.
Landscape plants can be fertilized in late February/early March, as soil temperatures warm up and fresh growth starts to appear. It's not a good idea to fertilize when the temperatures are heating up, as the plant roots are susceptible to damage from salts in soluble fertilizer (referred to as "burning"). You can apply a light dressing of fertilizer again in late September/early October. Follow package instructions to determine the amount of fertilizer to use. Enjoy gardening in your new environment!