Hyacinth heaving

June 2013 issue of the Cornell Flower Bulb Research Program Research Newsletter:

Heaving of hyacinths out of the pot (Figs. 1, 2) is sometimes a serious problem for North American forcers since most do not use the foam pad method common in Holland. We conducted a simple experiment to look at ways to solve or at least reduce this problem. We planted bulbs shallow, deeper, or literally on the bottom of the pot. With some, we sprayed non-toxic water-soluble glue onto the soil to glue it all together. On some, we wrapped two rubber bands such that if the bulb lifted up, the bands would push back down. With others we placed a circle of plastic mesh (with 3-4 mm grids) above or below the bulb with the idea the mesh reduce heaving by requiring the bulb to lift more soil (from on top), or toe whole weight of the bulb (if on the bottom).

Read the whole article.