500 Seeds Brussel Sprouts Catskill Sweeter with Frost Dwarf Non-GMO Sowing: Since frost brings out the best flavor in brussels sprouts, plant them late in May or early in June for a fall crop. Start Catskill Brussels sprouts seeds by planting them 1/2" deep in soil; when they grow to 6" tall, transplant or thin them 2' apart. Compress the soil around the seed and keep the ground moist. Compress the soil around the seed and keep the ground moist. Growing: Mulch to preserve the moisture in the soil before growing Brussels sprouts. Remove weeds carefully to avoid disturbing the plants. If heavy winds threaten the plant, provide a stake for support. As the leaves on the stem turn yellow, take them off so that the sprouts can freely develop. If aphids appear, eliminate them with a strong stream of water from a hose