Plant tulips in October through late November, when the soil has cooled to below 50°F. This temperature is essential to root development. Tulips will grow in most soil types, but if your soil is particularly sandy or heavy clay you would greatly benefit from loosening the soil and the addition of organic material such as compost, peat moss, etc. A few handfuls of pea gravel at the very bottom of the planting hole would also be beneficial as tulips demand excellent drainage.