What Do You Treat Straw Bales with Before Planting?

Watering

• First and foremost, the straw must be watered thoroughly every day for 10 days. This water helps the straw decompose more quickly so that the nutrients held within it become available to the plants. For the first three days of treatment, you will only be watering the bales; however, on the fourth day you will begin adding fertilizers as well as water.

Ammonium Nitrate

• Ammonium nitrate is a high nitrogen fertilizer that you will inoculate the straw with. Nitrogen is the most important of the many nutrients necessary for healthy plant growth. Straw is largely a carbon-based material, so without the addition of large amounts of nitrogen, you will not be able to successfully grow plants in straw. On the fourth through sixth days of treatment, sprinkle 1/2 cup of ammonium nitrate on each straw bale before watering the bale thoroughly. For days seven through nine, use half the amount of ammonium nitrate, 1/4 cup, before watering.

Standard Fertilizer

• On the final day of treatment for your straw bales, no more ammonium nitrate is necessary. However, a fertilizer with an even fertilization ratio, meaning a ratio of 7-7-7, 10-10-10 or 14-14-14 should be generously added to the straw before watering one last time. If you are using a 7-7-7 fertilizer, add 2 cups. If you are using a 14-14-14, use 1 cup. If you are using a fertilizer with a number in between, calculate and add the fertilizer accordingly. This fertilizer adds the phosphates and potash to your straw that plants depend on almost as much as nitrogen, but require in smaller doses.

Preparation and Planting

• The day after adding your balanced fertilizer to the straw, you will be ready to begin planting. Add an inch-thick layer of potting soil or compost on top of the bale before planting your seedlings. Make slits as opposed to holes in the bales, and use a hand shovel or a spatula to divide the tightly knit straw just wide enough to set the root ball of your plant in the straw.