Drainage - When an area is poorly drained, four techniques can be used to improve it. They are:

Adjusting the soil pH - The optimal pH range for most flower bulbs is 6 to 7. Therefore, the soil should be tested. If the pH must be adjusted, the following information can be used as guidelines (Reference: Sudbury).

The amount of additive required to change pH depends on the type of soil. There are three basic soil types:

The following additives can be used, to raise the pH 1 unit:

Additive

Pounds/1,000 Sq. Feet

Ground or dolomite limestone

68

Hydrated or spray lime 

50

Marl or wood ashes

68

Oyster shells

68

Burnt lime

38

The following additives can be used, to lower the pH 1 unit:
Additive
Pounds/1,000 Sq. Feet
  Aluminum sulphate 15
Compost 150-200  
Manure  50
Sludge  50
Green manure crop 10-12 oz of seed
Flowers of Sulfur    15

NOTE: For sandy soils use 33% less. For silt or clay loam soils use 15% more.

All additives used to raise pH should be incorporated into the soil at least one week before fertilizer is applied. Hydrated or spray lime reacts almost immediately. Other additives take months and, therefore, should be applied in the fall of the year for the next growing season. Never apply more than 50 lbs. of lime per 1,000 sq. ft. per application and never mix fertilizer with lime.

Preplant Weed Control - Glyphosate (Roundup™) can be used to establish a weed free site before bulbs are planted (Reference: Skroch). Total site preparation time is approximately four to six weeks.

In order to plant flower bulbs in September to November, site preparation must begin in summer (August). Total preparation time is approximately four to six weeks using the following method:

Consumer Horticulture | Bulletin 41: Narcissus