What works better for a plant, foliar spraying or soil drenching?

Question

seaweed extract
miracle-gro

Answer 1

depends on what you are planting

Answer 2

It seems you are asking organics VS synthetics, can plants tell the difference. Personally I use organics because I already have acidic soil. Acidic soil has less available soil nutrients. So I regularly spray my roses to give them a boost in performance. My soil is already fertile, and well mulched I just like to get a better display on plants that are not as happy in acidic soil. I do this to prevent deficiencies in the minor elements. So I prefer organic foliar sprays and I use compost to fertilize the soil and help control pH. I use Growmore seaweed extract ( 0.10-0.10-1.5) and Alaska® Fish Fertilizer 5-1-1. I also spray with compost tea and alfalfa tea at times.
If you have heavy soil you may have very different needs.

Miracle Gro LiquaFeed 12-4-8
LiquaFeed® Bloom Booster 12-9-6
This is a pretty heavy dose of nitrogen so I would use it on foliage but not if I was trying to support a heavy flowering.
This kind of addition will tend to make soil more acid so force one to keep trying to balance pH and soil nutrient availability in weathered soils.

The idea behind seaweed is that it has growth hormones (cytokinins, gibberellins and indole auxins). The hormones may work with other plants. They definitely have micronutrients including iron, zinc, copper, molybdenum, cobalt, boron, manganese and magnesium.
Kelp/seaweed meal varies in its NPK by manufacturer but is always much lower numbers than a synthetic. Nitrogen is a form that leaches less so alters the soil pH less. It also stays around to be a plant nutrient longer.
http://organicgardens.suite101.com/article.cfm/organic_liquid_fertilizers

Answer 3

soil drenching works a lot better because you are providing nutrition to the roots whatever you put in the gorund the roots will take up so soil drenching is much recommended