How to Grow Hollyhocks in Houston, Texas

Choose a planting location in full sun that is sheltered from the wind. Prepare the planting bed in the spring or fall one week before your intended planting date. Till under any weeds or grass and work a layer of organically enriched topsoil into the bed. Gardeners in the northern and western parts of Houston (north of Interstate 10 and west of U.S. Highway 59) likely have rich, loamy soil naturally. Those in other parts of the city may have to amend clay and other heavy soils to promote drainage or build raised beds and fill them with rich topsoil.

Water the hollyhock immediately after planting and at least once a week with an inch of water, keeping the soil continually moist but not soggy or waterlogged. Extended drought conditions and hot Texas summers may make more frequent watering necessary. Avoid splashing the leaves as much as possible when watering to help prevent fungal infection.

Prune hollyhock stems in July after the plant has bloomed, cutting the stems off just above the ground to produce a second round of flowers.

Fertilize hollyhocks just as they begin to bloom in the spring and again in midsummer when the next round of blooms are forming. Use 2 to 3 teaspoons of fertilizer per gallon of water when feeding your plants. Bloom fertilizers should be high in phosphorous and potassium but low in nitrogen, such as a 2-8-4 combination.

Inspect the leaves of your hollyhock plants regularly for signs of rust. Rust is a fungal disease and the most common hollyhock problem in Texas. Rust spots on the underside of leaves will be small, reddish and powdery. Spots on the tops of leaves will have more of a yellow or orange hue and may be larger. Remove any infected plants and burn them to prevent the spread of the disease.

Rake the area underneath your hollyhock in the fall to remove any weeds, dead leaves and spent blooms that have accumulated. Keeping the garden free of this debris helps eliminate rust and other fungal problems.