The First 40 Days of Cotton Growth and Why They Matter for Yield

Key Takeaways

• The first 40 days after planting establish the cotton plant’s yield potential and set the foundation for the entire growing season.
  
• Cotton has five main growth stages: germination and emergence, seedling establishment, leaf and canopy development, flowering and boll development and crop maturity.
  
• Optimal soil temperature (65°F at 4” depth for three days), moisture and seed-to-soil contact are essential for uniform emergence and healthy seedlings.
  
• Monitoring for weeds, insects (like thrips) and disease after emergence helps prevent stunting and delayed maturity.
  
• Eliminating weed competition and protecting against thrips with seed treatments or foliar sprays ensures steady growth through the seedling stage.
  
• As the plant develops vegetative and fruiting branches, managing soil moisture and fertility helps balance vegetative and reproductive growth.
  
• In favorable growing conditions, timely PGR use can help prevent excessive vegetative growth and keep the plant focused on fruit set.
  
• TerraFlow^® by UpTerra improves water infiltration, nutrient uptake and soil structure, helping cotton growers achieve measurable yield increases and more income per acre.

Management Tips to Optimize Vegetative Growth in Cotton

Many agronomists consider the first 40 days in a cotton plant’s development as the most critical for establishing yield potential. During the first month or so after planting, the crop is setting its foundation for the season. Production practices and environmental conditions during this window can significantly impact the crop’s health and development.  

Let’s explore the vegetative growth stages in cotton to learn how you can better manage your crop in those critical days after planting. 

Source: Plains Cotton Cooperative Association Facebook post

Main Growth Stages in Cotton

Cotton development is generally divided into five key growth stages:

• Germination and emergence
• Seedling establishment
• Leaf and canopy development
• Flowering and boll development
• Crop maturity

When the seed germinates and emerges, vegetative growth begins. The plant remains in the vegetative stage until the first floral buds, or squares, form five to eight weeks after planting (Texas A&M AgriLife Research and Extension Center at San Angelo). In this blog post, we’ll focus on cotton development up to the flowering stage.

Cotton Germination and Emergence

What’s happening

Cotton seed germinates when it has absorbed enough water to split the seed coat open. At that point, the radicle (root) begins to form. With adequate soil moisture and temperatures, this typically occurs 2 to 3 days after planting. 

The taproot continues to grow downward, while the hypocotyl (seedling stem) elongates to push the cotyledons up through the soil surface. Under ideal growing conditions, the seed leaves (cotyledons) will emerge after 50 to 70 growing degree heat units have accumulated. This typically happens 4 to 9 days after planting.

The cotyledons unfurl and serve as the initial energy source for the cotton plant until the first true leaves appear. Before they emerge, the cotyledons transfer stored nutrients from the seed to the developing seedling. After emergence, they begin to photosynthesize to produce energy from sunlight. 

Key management considerations

Germination and emergence are the critical first steps in establishing a high-yielding cotton crop. Roots are developing rapidly during these early stages, adding 0.5 to 2 inches per day, depending on soil moisture and temperature (Morgan, 2015). A majority of the crop’s root growth happens within the first 60 days after planting. Adequate soil moisture supports more vigorous crop emergence and root development during the first few weeks after planting. The longer it takes for a crop to emerge, the greater its risk for plant death and yield loss (Ritchie et al., 2007).

Protecting the cotyledon leaves after emergence is essential to maximize cotton yield potential. Stresses, including hail and insect or disease infestations, can damage these early leaves. Research has shown that cotyledon losses of 50%-75% trigger yield reductions of more than 30%. A complete loss of cotyledons reduced yield and quality traits such as boll size, micronaire and fiber strength and elongation (Verhalen et al., 2007).

Source: The Cotton Foundation, as cited in Oosterhuis, 1990

These factors can inhibit cotton germination and emergence:

• Cool soil temperatures
  • Optimal soil temperature for planting is 65°F at 4” depths for at least three consecutive days
• Planting too shallow or too deep
• Poor soil conditions for seed-to-soil contact
• Waterlogged, droughted or crusted soils
• Insect, weed or disease pressure
• Poor seed quality
• Extreme weather conditions after planting

Consider these management tips to promote strong cotton germination and emergence:

• Monitor soil temperatures and moisture ahead of planting
• Ensure a solid seedbed for optimal seed-to-soil contact
• Watch extended forecasts to avoid extreme weather post-planting
• Plant seed treated with fungicide and insecticide to protect from early-season pests
• Add a biological to support more vigorous emergence 

Seedling Establishment

What’s happening

A week or so after the cotyledons emerge and the seedling is established, the cotton plant’s first true leaves form. When this happens, the plant’s primary energy source shifts from stored nutrients in the cotyledon to sunlight via photosynthesis. At this point, true vegetative growth begins, with main-stem leaves forming at nodes along the main stem.

New nodes form along the main stem approximately every 3 days; they appear more quickly in the early growing stages than in later ones. The plant’s growing points on the main stem and fruiting branches expand, growing both upward and outward. 

Emerged cotton plant with cotyledon leaves and first true leaf
Source: University of Georgia Extension

Key management considerations

Scouting the crop after emergence is critical for identifying challenges or stresses that could slow growth and development. Early in the season, cotton is more vulnerable to weed pressure and insect damage. Eliminating weeds that compete for limited moisture and nutrients is important for maximizing the crop’s early-season growth. 

Thrips are a common early-season cotton pest, and they can cause damage to the plant’s growing points, resulting in plant stunting and maturity delays. Seed treatments and in-furrow insecticides can help protect the growing crop. However, if thrip pressure is high after emergence, a foliar insecticide applied at the first true leaf stage can help protect plants until the four- to five-leaf stage (Byrd, 2019). At this point, the crop is less susceptible to thrip damage.    

Typical early-season thrip-damaged cotton plant showing leaf puckering and feeding holes.
Source: University of Georgia Extension

Canopy Development

What’s happening

Four to five weeks after planting, the cotton plant expands its basic stem, root and leaf framework to form vegetative and fruiting branches. These branches will fill out the crop’s canopy and set the foundation for reproductive growth. 

Vegetative branches form at lower nodes on the main stem and grow nearly upright from a single growing point, similar to the main stem. These branches produce leaves that will help harness sunlight to produce carbohydrates for plant growth and development. Initially, the carbohydrates produced will be used to develop more roots and leaves to support rapid vegetative growth. However, as reproductive structures begin to form, the plant shifts carbohydrates to the developing fruit.

Fruiting branches have many growing points, causing them to assemble in a zig-zag pattern from the main stem. They usually begin growing at the fifth or sixth node on the main stem; however, plant stress, planting population, moisture availability, seed variety and temperature can affect fruiting branch placement (Texas A&M AgriLife Research and Extension Center at San Angelo, 2024). When moisture is limited, fruiting branches may form on lower nodes, resulting in a smaller plant with reduced yield potential. Alternatively, too much moisture and fertility early in the season can extend the first fruiting branch further up the main stem. This higher placement can delay boll development and maturity. New fruiting branches typically develop every three days, but this development also varies based on cotton variety and growing conditions. 

Typical cotton plant growth pattern

Source: Clemson Extension (adapted from Oosterhuis DM. Growth and development of the cotton plant. 1990)

Key management considerations

Cotton has an indeterminate growth habit, meaning it continues to grow vegetatively while simultaneously developing reproductive structures such as flowers and bolls. Under ideal growing conditions and high fertility, this can create management challenges for growers. Excessive vegetative growth can compete with reproductive growth for resources. Appropriate timing of plant growth regulators (PGRs) can help growers slow vegetative growth and encourage fruit set.   

As vegetative and fruiting branches develop, pay close attention to soil moisture and fertility to find the right balance for optimizing yield and boll maturity. At early bloom, count the nodes above the highest position white flower (NAWF). Generally, seeing seven or eight nodes at this time means vegetative growth is on track. If you have more than nine nodes, a PGR may be recommended to halt vegetative growth. Conversely, if there are six nodes or fewer, more irrigation or fertility may be required to stimulate vegetative growth (Brown & Sandlin, 2019). 

Source: University of Georgia Extension

How Long Is Vegetative Development in Cotton?

Under favorable growing conditions, the cotton progresses through vegetative growth stages relatively quickly. Typically, by the fifth week after planting, the first square develops and the crop transitions from vegetative to reproductive growth. The table below shows the average number of days and heat units required for cotton growth stages in the Mid-South. 

Source: The Cotton Foundation (modified from Oosterhuis, 1990)

Optimize Vegetative Growth in Cotton

The first 40 days of a cotton crop’s development are crucial for establishing top-end yield potential. Managing moisture is one of the most effective ways to support your crop during the foundational vegetative growth stages. TerraFlow^® by UpTerra helps you do that.

TerraFlow is a plug-and-play device that installs into your current irrigation line to enhance the water you’re already applying to your cotton. Using proprietary vortexing and frequency imprinting technology, TerraFlow reduces water’s surface tension and improves its movement across and into the soil. The result is better infiltration, improved nutrient uptake, increased moisture retention and more beneficial microbes working in your soil. 

And those benefits are helping growers achieve quantifiable results, even in the first year of installation. Here are just a few examples, straight from UpTerra cotton farms:  

• $70 more income per acre
• 6.7% yield increase
• 16.2% trash reduction at harvest
• 28.8% faster water infiltration
• 45% better soil aggregation

Interested in learning more? Contact an UpTerra team member for more information about how TerraFlow can support your cotton production goals.

UpTerra-treated cotton seedling. Treated plants showed more consistent emergence, larger root masses and more vigorous growth than plants irrigated with untreated water.

Vegetative Growth Stage	TerraFlow Benefit
Germination & emergence	Supports vigorous root growth and early root access to water/nutrients
Seedling establishment	Enhances root expansion and nutrient uptake during rapid vegetative development
Canopy development	Optimizes water/nitrogen use efficiency for balanced vegetative and reproductive growth; Retains more soil moisture to reduce plant stress

References

Brown, S., & Sandlin, T. (2019, October 3). How to Think About Cotton: Plant Growth Regulators. Alabama Extension. 

Byrd, S. (2019, Jun 1). Considerations for Cotton Planting and Early Season Growth. Oklahoma State University Extension. 

The Cotton Foundation & National Cotton Council of America. (n.d.). Growth and Development of a Cotton Plant. 

Morgan, G. (2015, June 2). Texas Row Crops Newsletter. How Waterlogged Soils Impact Cotton Growth and Management Decisions. 

Salman, N., Jones, M., Campbell, B.T., & Rustgi, S. (2024, August 19). Insights into Cotton Regrowth and Management. Clemson Extension Land-Grant Press. 

Ritchie, G. L., Bednarz, C. W., Jost, P. H., & Brown, S. M. (2007, June 1). Cotton Growth and Development. University of Georgia Cooperative Extension. 

Texas A&M AgriLife Research and Extension Center at San Angelo. (2024, July 8). How a Cotton Plant Grows. 

Verhalen, L. M., Bayles, M. B., & Greenhagen, B. E. (2007, January 9). 2007 Beltwide Cotton Conference. Cotyledons in Cotton: Who Needs ‘Em?