Notes

This page is a repository of all of the raw information that I have gathered regarding various aspects of growing chile pepper plants. Citations are provided by the numbers in parenthesis preceding each of the notes; these numbers are linked to the appropriate section of the References page.

When to start seeds
Starting seeds
Lighting
Early fertilization and watering
Indoor transplanting (re-potting)
When to transplant to garden
Garden preparation
Hardening plants
Transplanting to the garden
Ongoing fertilization
Basic pepper reproduction and genetics
Cross-pollination
Plant breeding
Saving Seed

Western Piedmont:

(Ref 3) Start seeds 6-8 weeks before the daily low temperature is expected to stay above 55 F. Per Greensboro climatological norms, mean daily low for May is 54.7 F. 6-8 weeks before 1 May is 1 Feb-15 Feb.
(Ref 5) Start seeds 8-10 weeks before last spring frost. Per Reidsville climatological norms, the average last spring frost date (1951-1980) is 7 April, with a standard deviation of 11 days. Allowing a 2 sigma margin of safety, latest expected last spring frost date would be 29 April. 8-10 weeks prior to this date would be 15-28 Feb.

Coastal Plains:

(Ref 5) Start seeds 8-10 weeks before last spring frost. According to my analysis of 30 Year NC Climatological Data for weather stations in my area, the last frost in my area is 90% likely to have occurred by 17 April. This date would be my "transplant to the garden" date; since it takes me about 2 months to get from seed to garden (62 days in 2004, 65 days in 2001) I should start seeds 8 weeks before this, or about 17 February.

General:

(Ref 4) In North Carolina, start seeds 1 Feb-1 Mar.
(Ref 11) Start seeds 6 to 8 weeks before target transplant date.
(Ref 6) Favorable signs of the moon for planting are: Taurus, Cancer, Libra, Scorpio, and Pisces. Favorable phases of the moon for planting are the first and second quarter, but not during a phase change.

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(Ref 11) Fill a jar with water and pour the seeds into it. Discard any seeds that float. Inspect the remaining seeds and discard any that are "undersized, shriveled, discolored, cracked, or otherwise damaged" (Ref 11, p. 93).
(Ibid.) Germination percentage and germination rate can be increased by soaking the seeds in a 100 ppm (parts per million) solution of the plant hormone gibberellin for one to two hours before planting.
(Ref 1) Plant in a light soil mixture, such as potting soil and vermiculite/pearlite.
(Ref 11) Plant in a 1:1:1 mixture of sterile potting soil, vermiculite, and pearlite. The authors of Reference 11 advise using peat moss sparingly (if at all), as "peat moss is difficult to wet, is too acid, and compacts badly" (Ref 11, 103).
(Ref 2) Start seeds in containers with a maximum depth of 3-4" and having hole(s) in the bottom to insure positive drainage. Use a mixture of moss (peat or sphagnum), vermiculite, and pearlite.
(Ref 3) Plant three seeds per pot and thin to one when the seedlings are about 1" tall.
(Ref 5) Plant seeds 1/4" deep and keep covered with plastic until seedlings sprout.
When I start seeds indoors, I put fluorescent lights close to the tops of the pots on a 24 hour light cycle to keep the soil warm. I also use a cut-up Ziploc(R) Vegetable Bag rather than solid plastic. This allows the airspace over the soil to 'breathe' a bit.
(Ref 11) Summarizing a classic study of the germination of Bell Pepper seeds, Reference 11 states that for optimal germination, pepper seeds should be germinated and grown at temperatures of 70 F (21 C) or higher, and seedlings should be watered with warm water from above (as opposed to being subirrigated).

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(Ref 1) Use fluorescent bulbs, 1-2" over plants, raising lights as necessary as plants grow. Use an 18 hour light cycle.
(Ref 2) Use fluorescent bulbs, within 1" of plants. Raise as necessary. Use a 14-16 hour light cycle.
My experience with starting plants indoors has shown that fluorescent bulbs, kept within 1-2" of the plant tops, on an 18 hour light cycle, provides excellent results- quick, compact growth until the plants are big enough to harden and transplant outdoors. The fluorescent lights won't burn the plants (unless the leaves actually *touch* the bulb), and they produce a small enough amount of heat that ventilation in an enclosed grow area is not an issue.

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(Ref 2) Start fertilizing when first leaves appear. Use half-strength Miracle-Gro solution 1-2 times per week.
(Ibid.) Wait until the top of the soil becomes dry before watering to help prevent fungal growth.
(Ref 5) Phosphorous is critical for good root development. Early fertilization with a high-P, non-burning liquid fertilizer is therefore a good idea.
Miracle-Gro Quick Start (4-12-4) is a good high-P non-burning liquid fertilizer.

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Re-pot plants whenever their size, and the size of the pot that they are in, dictate. Use regular potting soil. Water the plants well several hours before transplanting. After re-potting, fertilize with Miracle-Gro Quick Start.
(Ref 6) Favorable signs of the moon for planting are: Taurus, Cancer, Libra, Scorpio, and Pisces. Favorable phases of the moon for planting are the first and second quarter, but not during a phase change.

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(Ref 3) Transplant about two weeks after the daily low temperature is expected to stay above 55 F. Per Greensboro climatological norms, mean daily low for May is 54.7 F. Thus, transplant around 15 May.
(Ref 4) In North Carolina, transplant April - May.
(Ref 6) Favorable signs of the moon for planting are: Taurus, Cancer, Libra, Scorpio, and Pisces. Favorable phases of the moon for planting are the first and second quarter, but not during a phase change.

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(Ref 3) Soil pH should be 5.5-7.0. Spacing between rows should be 2-3'.
(Ref 4) Soil pH should be 6.0-6.5. Use lime to adjust. Spacing between rows should be 3.0-3.5'.
(Ibid.) Practice crop rotation and avoid planting peppers in fields that were used the previous year to grow any of the following: cotton, tobacco, eggplant, peppers, and Irish potatoes. This helps avoid problems with nematodes, fungus, and diseases.
(Ibid.) Fertilize per soil test by broadcasting fertilizer into tilled soil and raking it in, about two weeks before expected transplant date.
(Ibid.) If no soil test was performed, fertilize as above using 3# 10-10-10 per 100 square feet of plot area.

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(Ref 4) About 7-10 days before expected transplant date, begin hardening plants progressively by limiting water and exposing to gradually increasing amounts of direct sunlight and wind.
(Ref 2) Essentially as above.
(Ref 11) Essentially as above. Per this reference, hardening causes the plants to store more carbohydrates and causes the cuticle on the leaves to thicken, decreasing the rate at which the plant loses water via transpiration.

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(Ref 2) Transplant to rows with 10-15" plant spacing.
(Ref 3) Transplant to rows with 18" plant spacing. Use paper cups with the bottoms cut out as protective collars for the transplants. Press the bottom of the cup 1/2-1" into the ground.
(Ref 11) Reference 11 discusses the virtues of close plant spacing, quoting Arthur Pratt, professor emeritus at Cornell University: "...pepper plants grow almost twice as tall when they're tightly spaced, and then there's usually less sunscald on the fruit because they are better shaded by the leaves" (Ref 11, 108). Professor Pratt recommended planting on one-foot centers.
(Ref 4) Transplant in the late afternoon to avoid wilting.
Water the plants well several hours before transplanting. After transplanting, fertilize with Miracle-Gro Quick Start.

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(Ref 2) Nitrogen is for leaves, and too much nitrogen will impact the size of the harvest.
(Ref 11) Too much nitrogen will cause a pepper plant to drop flowers and small peppers and return to vegetative growth.
(Ref 3) Fertilize twice, when plants are 8" tall and 1' tall. Sidedress with 5-10-5 at 5 oz / 10' of row.
(Ref 4) Sidedress 2-3 times, starting two weeks after transplanting. Use 10-10-10 at 5 oz / 10' of row.
(Ref 11) After transplanting to the garden, fertilize only if the plants show signs of nitrogen deficiency, and then fertilize sparingly.

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(Ref 11 p. 118) Peppers are considered to be self-pollinated, but are strongly subject to cross-pollination (see Cross-pollination section below)
(Ibid. p. 171) Pepper flowers are perfect, meaning that they contain both male and female sexual organs (stamens and stigmas, respectively).
(Ibid.) Sexual reproduction occurs as a result of contact between a grain of pollen, released by a mature anther (the 'business end' of the stamen), and a stigma. "[T]he pollen develops a tube that grows downward through the style (the base of the stigma) and into the ovule. Male and female gametes (reproductive cells) unite in the ovary. After fertilization, the ovule begins to develop and the result is a seed". Note that one grain of pollen produces one seed, so that if a flower is cross-pollinated by pollen from several different plants, the seeds contained in the resultant fruit can produce widely varying sibling plants. Thus all the seeds contained in a single pepper, if the pepper was produced under conditions permitting cross-pollination, will not necessarily produce plants of a single variety.
(Ref 13) The inheritance of traits (e.g. plant size, fruit shape, immature and mature fruit colors) is controlled by genes, which "are the basic unit of heredity".
(Ibid.) "Each gene may... be present in multiple versions called alleles, each producing a slightly different effect on the same trait. For example, a gene for petal color in flowers might have an allele for red, and an allele for white."
(Ibid.) "The genome is [the] sum of an organism's genes".
(Ibid.) "Phenotype is the physical expression of a trait or traits in the individual. 'Pink Flowered' is an example of a phenotype. Genotype refers to the genetic basis for a trait or traits, for example 'red and white alleles.' The phenotype of an individual is determined by the actions of all genes (genotype) in combination with each other and the environment."
(Ref 11 p. 171) A seed has two genes for each trait- one gene from each parent.
(Ibid. p. 172) A plant that produces offspring that are identical to itself when self-pollinated is said to be a 'true-breeding' plant.
(Ibid.) "The offspring of a [cross-pollination] are called the first filial (F₁) generation." "The offspring... of [the] F₁ generation are called the second filial or F₂ generation."
"To produce hybrid seeds, two inbred parent lines are developed, each possessing beneficial traits. These parent lines are then crossed in a controlled way to produce seeds, called the F1 generation. ... The primary advantage of hybrid varieties is the fact that when two distinct inbred (or genetically homozygous) parents are crossed, the offspring often grow much larger and more vigorously than either of the parents. This phenomenon, known as heterosis, has been exploited in many crops to improve yield and quality." (Kent J. Bradford. "Seeds: The Delivery System For Plant Biotechnology." Seed Biotechnology Center, University of California.)

BUT

(Ref 11 p. 173) "Seed taken from... mature [F₁ hybrid] pods will not produce peppers true to type, and numerous plants unlike the parents will result. Therefore, saving seed from hybrids is seldom worthwhile."
(Ref 13) "The F2 generation has the most visible genetic variation of any generation...and contains all combinations of parental traits."
(Ibid.) "If F2's are allowed to cross-pollinate each other, the parent genomes will become increasingly mixed. An intermediate type which is a blend of the parent types will come to prevail [after several generations] under [repeated] cross-pollination. Although the progeny will become more and more homogenous in appearance... a great deal of genetic variability... will be maintained in equilibrium. Occasionally, unusual types will crop up out of this genetic variability."
(Ibid.) "If [F2's] are self-pollinated instead, the variability in the F2 generation [will] be maintained in distinct lines [each of] which will become more and more stable [within itself] with each generation... By the time the lines have stabilized in the F5 or F6 generation...individuals in [each line] will be close to identical. However, the variability between lines will be maintained."

(Ref 11 pp. 118-9) Studies have shown that, for some Capsicum species, a significant percentage of pollinations are actually natural cross-pollination via insects as opposed to self-pollination.
(Ibid. p. 119) "Any two varieties of the same pod type or species will cross." Thus, for example, any C. annuum can cross-pollinate any other C. annuum, and the seeds of the pod produced by this cross-pollination will then produce a natural hybrid of the two parents.
(Ibid. p. 119) The above two points "[demonstrate] the need for strict isolation in the production of commercial seed."

(Ibid. p. 120) Cross-pollination between Capsicum species depends upon the exact species involved:

	C. annuum	C. baccatum	C. chinense	C. frutescens	C. pubescens
C. annuum	Prolific	Sporadic	Prolific	Sporadic	Not at All
C. baccatum	Sporadic	Prolific	Sporadic	Sporadic	Not at All
C. chinense	Prolific	Sporadic	Prolific	Sporadic	Not at All
C. frutescens	Sporadic	Sporadic	Sporadic	Prolific	Not at All
C. pubescens	Not at All	Not at All	Not at All	Not at All	Prolific

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(Ref 11 pp. 173-4) Since pepper plants can cross-pollinate, it is important to take appropriate measures to prevent undesired cross-pollination if you want to obtain pure seed from a plant. This will require physical isolation of the plant from insects; common methods include cages covered with small-mesh netting, enclosing a single branch having flower buds (but no open flowers) in a paper bag for a week, and placing a gelatin capsule over an unopened flower bud: "[t]his will keep the flower closed until it has selfed. As the fruit grows, it pushes the capsule off." Tag spots adjacent to self-pollinated flowers to insure that you harvest and save the correct pods later.
(Ibid. pp. 174-5) Cross-pollination for breeding purposes should be done by hand to insure that the desired plants (and only the desired plants) are crossed. Very high temperatures and high humidity degrade pollen. Plants should be pollinated on dry mornings between an hour after sunrise and 11 AM. The most important aspect of cross-pollination is preventing the flower from self-pollinating. "Chose flower buds that are one to two days from opening. These buds are plump and white. Using forceps [and a magnifying glass], remove the petals and stamens... leaving the calyx and pistil. ... From the male parent, either pull the anther from an opened flower and gently touch the anther to the stigma to transfer pollen, or take the spear needle, glean pollen from the anther, and place that on the stigma. ... Because peppers are not wind-pollinated and insects will not visit the flower after the petals are removed, no other flower protection is necessary." Tools should be disinfected with rubbing alcohol and allowed to air-dry prior to cross-pollination. Cross-pollinate multiple flowers to improve the chances of producing a crossed fruit.
(Ref 13) "Inbreeding leads to genetic uniformity and stability, and outbreeding leads to genetic variability and instability."
(Ibid.) "The basic method for developing a new variety in a self-pollinated crop is to hybridize (cross) individual plants and select a new variety from the progeny ... Sometimes a cross between excellent parents produces poor progeny, or vice versa. The outcome of a cross depends on how well the parents combine, or 'nick'."
(Ibid.) "If you must introduce additional parents into a cross to contribute certain traits, make the crosses early in the program. For example, with three parents make a cross between two parents and then cross the third parent to the progeny of the first two. To cross four parents (P1, P2, P3, P4), cross P1xP2 and P3xP4, then cross their progeny (P1xP2)X(P3xP4). It is best to make all crosses in both directions, i.e. use each variety as the female parent. This is because some genes can only be inherited from the female parent."
(Ibid.) Mass Selection method: "Mass selection refers to the selection of single plants based on phenotype alone. It is an easy and fun technique, and one which farmers have practiced for millenia. In a self pollinated crop it's as simple as making a cross and selecting the best plants. Constantly rogue out any undesirable plants and mark plants that are exceptional for a certain trait with ribbons or stakes, then select the plants with the most marks at the end of the season. For self pollinated crops, the major disadvantage to mass selection is that selections made on phenotype alone are inaccurate. For hard to evaluate traits, the response to selection with mass selection is often the slower than other methods. Mass selection can be very fast when traits are easily evaluated by eye, though. Mass selection is a very easy and accessible method when adapting a landrace (variable variety) to an area, or when selecting for clear-cut traits."
(Ibid.) Pure Line method: "A pure line is a variety that has been inbred to the point of genetic uniformity. The simplest inbreeding technique is called the pure line method. Here's how to do it. Make an individual cross and advance it to the F2 generation without making any selections. Grow out as many F2 plants as possible. Select the best plants from the F2 generation and keep their seed separate from each other. Plant out all the seed from a [given] F2 individual in a separate row or block. Each row or block constitutes an F2 family. Evaluate each family as group, and advance only the best families to the next generation. Each generation, evaluate as many plants from each family as you have room for. After several generations, you will be comparing the very best families on a large scale, allowing you to make subtle discriminations between them. The best family should be a stable variety by the end of the process (F5, F6, or F7 generation)." Obviously this method requires that you prevent any cross-pollination after the initial cross to keep the families pure. I would think, although the reference does not state this, that you would use seed from the best plants in each family to produce the next generation of that family.
(Ibid.) Single seed descent method: "Single seed descent is so named because one seed is saved from each F2 plant and advanced to the next generation. (In practice, it is best to save extra seeds as insurance against accidents.) Every generation thereafter, one seed is saved from each plant. Thus, the number of plants never grows beyond the amount in the F2 generation. No selection is practiced until the F2 lines are stable (no longer varying from generation to generation).The plants can be grown in any environment until selection is practiced. This allows for growing an extra generation each year in a greenhouse or winter nursery if it is available. The advantage of the technique is that a large number of stable lines are produced very quickly. Because the greatest variation is present in the F2 generation, this method also preserves the greatest amount of variety available for selection in a stable line."

See Cross-pollination above.
(Ref 11 p.94) Refers to a 1986 "study [which concurs] with our observations over the years, [indicating] that the highest germination percentage occurs in seed harvested from early [ripe] pods that are dried for between one and four months" prior to harvest of the seed. Important factors: early pods, fully ripe pods, and extended drying period in the pod.
(Ibid. p.94) The extended drying period cited above is referred to as after-ripening, and corresponds to a decrease in seed moisture content from about 34% to about 7%.
(Ibid. p.176) On average, pepper seeds will remain viable for 2 years; storage conditions can greatly extend this period.
(Ibid. p. 176) After after-ripening, seeds should be removed from the pods and stored in moisture-proof containers kept in a refrigerator.


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