Lower and Upper Leaf Symptoms (MOBILE NUTRIENTS) – Wrap up

I have listed below links to the posts that involve mobile elements. Mobile elements are more likely to exhibit visual deficiencies in the older leaves, because when these nutrients are limited they will be exported from the older leaves to the new growth. You will see the problems first on the lower leaves as the nutrients are moved to the newer fast growing leaves at the top of the plant.  So, when you see symptoms develop on lower leaves, read the posts for these nutrients and see if one is lacking.






The immobile elements tend to occur in new growth, since when they become limited, they will not be available to new growth. So, when you see symptoms develop on upper/new leaves, read the posts for these nutrients and see if one is lacking.





As always, E-mail me with any questions.
Good Growing,
Dr. E.R. Myers


Nutrient Basics -- Zinc

Zinc plays a roll in the same enzyme functions as manganese and magnesium. More than eighty enzymes contain zinc. Zinc participates in chlorophyll formation and helps prevent chlorophyll destruction. This means zinc deficiencies look similar to nitrogen deficiency with rolled leaf margin. Chlorosis shows up first in young leaves, which are also reduced in size. Zinc deficiency may also produce "rosetting"; the stem fails to elongate behind the growing tip, so that the terminal leaves become tightly bunched. Zinc deficiencies appear as chlorosis in the inter-veinal areas of new leaves Zinc deficiency produces "little leaf" in many species, especially woody ones; the younger leaves are distinctly smaller than normal

Zinc also gets locked out due to high pH. Zn, Fe, and Mn deficiencies often occur together, and are usually from a high pH. Don't overdo the micro-nutrients- lower the pH if that's the problem so the nutrients become available. Too much zinc is toxic. Foliar feed if the plant looks real bad. Use chelated zinc.

Zinc toxicity can occur when adding too much zinc and in soils excessively high in phosphates, nitrogen, calcium, or aluminium. Excess Zinc is extremely toxic and will cause rapid death. Excess zinc interferes with iron causing chlorosis from iron deficiency. Excess will cause sensitive plants to become chlorotic.

Good Growing,
Dr. E.R. Myers


Nutrient Basics -- Magnesium

Magnesium (Mg) is vital for photosynthesis since it is a part of the chlorophyll molecule. When you add Mg the plants will become a dark green. Magnesium is important also because it facilitates the use of nitrogen, phosphorus and sulfur. Also, Mg is needed in the formation of some plant proteins.

Signs of a Magnesium Deficiency -- For most plants a Mg deficiency first shows up in the lower leaves as discoloring in the veins. They first turn yellow, then orange and finally brown. Plant leaves will feel thin, brittle and sometimes cup upward.

Causes of a Magnesium Deficiency – soils that are too wet, (if growing in soil the top of the soil in the pot should be dry before watering.) Low pH (acidic) or soils high in peat or sand.  Moreover, soils given a high concentration of potash fertilizers or calcium can also show signs of an Mg deficiency. Mg can get locked-up by too much chlorine or ammonium nitrogen. Keep in mind you do not want to overdo Mg or you'll lock up other nutrients.

Cures for a Magnesium Deficiency -- Epsom salt is a cheap way to add Mg, using one table spoon per gallon once a month should suffice. Also, dolomite lime will add Mg, Calcium and keep the pH in a good range for most plant growth. When mixing up soil, use at least 2 teaspoon dolomite lime per gallon of soil. I use twice that personally.
For a quick correction of an Mg deficiency you can foliar fed the plants with ½ teaspoon/quart of Epsom salts (first dissolved in some hot water).
If your water is above 200 ppm, the hard water may lock out Mg with all of the calcium in the water. Either add a 1/4 teaspoon per gallon of Epsom salts or lime or invest in a water filter from HTGSupply.com (LINK to water filters).

Good Growing,
Dr. E.R. Myers


Nutrient Basics -- Potassium

Potassium (K) is important for the formation of flowers, fruit, and leaves. It also helps photosynthesis at low light levels and in internal water regulation. I have read it improves flavor in fruit, vegetables and flower color. Potassium is also linked to insect damage protection, disease and frost protection. Lack of potassium will reduce yield and quality.

Signs of a Potassium Deficiency --Older leaves are initially chlorotic becoming mottled or spotted, root systems are poorly developed and, fruit ripens unevenly. These symptoms will first apparent on the tips and margins (edges) of the leaves. Stem and branches may become weak and easily broken, the plant may also stretch. The plant will become susceptible to disease and toxicity. Also, a potassium deficiency will result in poor storage qualities (storage of herbs link)

Potassium can be limited in plants by too much sodium (Na) which displaces potassium, causing a deficiency. Sources of high salinity are: baking soda (sodium bicarbonate "pH-up"), too much manure, and the use of water-softening filters (which should not be used). If the problem is Na, flush the soil. K can get locked up from too much Ca or ammonium nitrogen, and possibly cold weather/ temperatures.

Organic sources of potassium are kelp or any seaweed and wood ash. Potassium toxicity is rare so make sure to give plants potassium in all stages of growth. I do not like to use fertilizers that lack potassium as the sole source of nutrients.

See my post on how potassium can affect pH

Good Growing,
Dr. E. R. Myers


Nutrient Basics - Phosphorus

Happy Independence Day!

Phosphorus (P) is also a vital nutrient for all plants that needs to be available to plants in all stages of growth. Phosphorus is the second number in fertilizers, so that a 5-15-5 fertilize would be 15% phosphorus. Specifically, phosphorus is crucial in root formation, flowering, fruiting and ripening. So, you should provide your plants with a fertilizer that has the middle number as the highest when you have seedlings, newly rooted cuttings, and from beginning to end during flowering/fruiting.

Signs of a Phosphorus Deficiency -- Early in the deficiency, plants look almost too healthy with what appears to be normal but undersized plants with dark green leaves. However, you may notice the leaves and or their veins and leaf stems (called petioles) frequently changing to purple, especially the undersides of leaves. Leaves may curl under with some plants. Sometimes the leaves will turn a gray brown with a phosphorus deficiency and you may mistake this for a fungal infestation. Look for the color change to be at the leaf tips with a phosphorus deficiency where as a fungal infestation will be all over the leaf in a more random pattern. Fungi can develop when water is allowed to remain on the leaves if you mist your plants or they are growing outdoors. Cold water can also be a cause of spotting. Use room temperature water when watering and misting. You will notice very poor flowering and fruiting if you have a phosphorus deficiency.

Phosphorus Deficiency – can occur in cold, wet or very acidic (below pH5) soils; also very alkaline soils (above pH 7.3). You will need to adjust the pH if it is below 5 or above 7.3 since no matter how much fertilizer you add it won’t be available to plants at those extreme pH’s. You should also consider potting up your plants with a pH problem the new soil will be a quick fix but you should still adjust the pH so the problem does not come back.

Bone meal is a good organic source of phosphorus and you can add this to a soil mix.

Good Growing
Dr. E.R. Myers


Nutrient Basics – Nitrogen

After reading this post, be sure to see how different forms of nitrogen affect pH (LINK)
Nitrogen (N) is a vital nutrient for all plants and it should be made available to plants in all stages of growth, although it should be given in lesser amounts during flowering. It is always listed as a percentage of every fertilizer as the first number. For example, a fertilizer listed as 5-1-2 would contain 5% nitrogen. Nitrogen is needed in all organisms as part of their DNA, it is also needed in many enzymes which regulate all metabolic activity in plant cells. Nitrogen will promote increases in stem and leaf growth and causes leaves to have dark green growth.

Sign of a Nitrogen Deficiency -- Plants will exhibit slow growth and will be stunted. If the problem is not corrected yield will be significantly reduced. The first thing you will notice is that older leaves become yellow (chlorotic). Nitrogen deficient plants will exhibit uniform light green to yellow color on older leaves, these leaves may die and drop. This color change will begin at the tips of leaves at the bottom of plant especially older leaves and the color change / yellowing gradually spreads up the plant to the top. Please note that many plants will exhibit these symptoms during flowering which is normal.

Nitrogen Deficiency Causes -- You can get a deficiency in fast growing crops, so if you are growing a plant that grows fast feed it a lot of nitrogen (never more than recommended by the manufacture!). You will also get a deficiency if you grow in very sandy soils (sand promotes good drainage but holds no nutrients for plants) or if you grow plants in soils with low in organic material (See compost link). Also, excessively wet soils and high or low pH can cause nitrogen deficiency. After you check the pH and adjust it to your plants optimal pH you can add Nitrogen fertilizer. The actual number is not so important as making sure the first number is the highest.

Nitrogen Toxicity is possible, so never over do it! With nitrogen toxicity leaves are often dark green and in the early stages plants are abundant with foliage. Eventually leaves will dry and begin to fall off. If you think you killed your plants by over doing nitrogen check and see if the root system is under developed or deteriorated, this is a sure sign you added too much nitrogen.

Organic sources of nitrogen are best in my opinion, you can get nitrogen in blood meal, most guanos manures and for free in urine. One cup of urine per gallon is a free source of nitrogen.

Remember though that if you are going to flower or fruit your plants you want to reduce the nitrogen percentage and have phosphorus (the second number in fertilizers) be the highest… Too much nitrogen delays flowering. Plants should be allowed to become ALMOST nitrogen-deficient late in flowering so that it does not inhibit flowering and I have read low nitrogen late in flowering can increase fruit flavor.

Good Growing,
Dr. E.R. Myers