I have several cape gooseberries flowering like mad, they are vigorous, however all the new growth is turning yellow and falling off. My first berry which was developing also turned yellow and fell off. What could be the issue? My soil is sandy and supposedly perfect for these plants.
Sand is poor at holding nutrients, and only some nutrients are mobile in plant tissues. Mobile nutrients like N, P, K, Mg can be "borrowed" from existing plant tissues to provide the building blocks needed for new growth to come on line, but immobile nutrients like Ca and most micronutrients CANNOT be "borrowed" from existing tissues. The immobile nutrients must be present in the nutrient stream at all times. Deficiencies that show up in new foliage are almost always one of the least mobile nutrients - Ca or a micronutrient.
Ca deficiencies usually manifest themselves in distorted or mal-formed new growth. Iron, Zinc, and Manganese deficiencies are all known to cause chlorosis in new growth. A soil test will tell you what you need to do; or you can take the shotgun approach and use something like STEM, Micromax, EJ Microblast, as a source of micronutrients; or you can do some research, looking for a granular fertilizer with somewhere near a 3:1:2 NPK RATIO (Ratios are different than NPK %s. 20-20-20 is a 1:1:1 ratio, while 24-8-16, 12-4-8, and 9-3-6 are all 3:1:2 RATIOS. A fertilizer's ratio is much more important than it's NPK %) that also reports all of the micronutrients essential for normal growth on the package.
Al
