Can I foliar feed with Reiziger nutrients?

Yes.

Make sure you use a weaker nutrient solution than you would for root feeding. Avoid foliar feeding in the heat of the day and in excessive sunlight. Generally, the best time to foliar feed is in the early morning or late afternoon. For best results, ensure you spray the undersides of the leaves. This is where the stomata or “lungs of the plant” are located, and where maximum absorption occurs.