Winter Survival | ScienceGate

The winter hardiness of many groundcover cultivars in northern Illinois is not well-known. This study was designed to evaluate the survival of 172 plants used in the groundcover path at The Morton Arboretum. Once a month, from Sept.1997 to Jan. 1998, the plants chosen for this study were visually evaluated and their vitality rated on a scale of 1 to 5 (1 = alive, 5 = dead). All nine cultivars of Euonymus fortunei remained virtually unchanged throughout the study period. Among six cultivars of Hedera helix, only `Gold Heart' showed minor damage in November. Nine Heuchera were evaluated and all exhibited excellent resistance to cold temperatures. While all the Pulmonarias studied showed some cold damage by November, `Bielefeld Pink', `Little Blue', `Roy Davidson', Pulmonaria longifolia var. cevennensis, and Pulmonaria officinalis `Sissinghurst White' fared the best for the longest period of time. Five cultivars of Pachysandra terminalis were included in this study. None had significant damage until November, and then only rated a “2.” Of the eight Ajuga evaluated, Ajuga pyramidalis `Metallica Crispa', and Ajuga reptans `Braunherz', `Catlin's Giant', and `Gaiety', exhibited the best cold resistance. Four Polygonums varied widely in their response to cold temperatures, but all showed signs of severe damage in November. Polygonum `Border Jewel' exhibited the best tolerance, rating a “1” in October, but in November it was given a rating of “4.” Their recovery in spring will be compared.

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Influence of Planting Stock Clove Size, Nitrogen Rate, and Planting Method on Elephant Garlic Production

HortScience ◽

10.21273/hortsci.33.3.517f ◽

1998 ◽

Vol 33 (3) ◽

pp. 517f-518

Author(s):

Jeanine M. Davis

Keyword(s):

Survival Rates ◽

Ground Level ◽

Winter Survival ◽

Nitrogen Rate ◽

Planting Stock ◽

Mild Winter ◽

Allium Ampeloprasum ◽

Planting Methods ◽

Planting Method ◽

Nitrogen Rates

To produce large elephant garlic (Allium ampeloprasum L.) bulbs in the southeastern United States, stock cloves must be planted in the fall. During extremely cold winters, however, winter survival rates can be very low. A 2-year study was undertaken to examine practices to increase winter survival rates. Two clove sizes (≤20 g or >20 g), three nitrogen rates (112, 224, and 336 kg/ha), and three planting methods (flat, mulched, and hilled) were tested in a RCB design with four replications. For all planting methods, cloves were set in a shallow trench and covered with soil to ground level. This was also the flat treatment. For the mulched treatment, 7 cm of straw was spread on top. For the hilled treatment, soil was mounded 10 to 15 cm high over the ground level. Cloves were planted in early October and harvested in mid-June. Use of large planting stock cloves increased winter survival rates during the harsh winter, but had no effect during the mild winter. Both years, winter survival was reduced with the flat treatment. Yields of marketable bulbs were 4 to 5 times higher when >20 g cloves were planted than when ≤20 g cloves were used. Nitrogen rate and planting method had no effect on yields. The >20 g cloves also produced larger bulbs than the smaller cloves. Of the three planting methods, the flat treatment produced the smallest bulbs. Bulbs were much larger following the mild winter than the harsh winter.

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