Apple

Overview

The Apple Rootstock Project focuses on growing genetically unique apple seedlings to identify vigorous, locally adapted rootstocks while simultaneously developing new apple cultivars.

Rather than relying solely on commercially available rootstocks, this project evaluates seedlings grown under Pacific Northwest conditions.

Current breeding material includes:

• Honeycrisp
• Cosmic Crisp
• Redlove Era
• Redlove Calypso
• Redlove Odessa

Additional red-fleshed cultivars will be added as the project expands.

Research Objectives

This project follows two primary goals.

Rootstock Selection

Honeycrisp and Cosmic Crisp seedlings are being grown and evaluated for:

• Vigor
• Cold tolerance
• Root development
• Adaptability
• Long-term rootstock potential

Most seedlings will ultimately become experimental rootstocks for future grafting work.

Red-Fleshed Apple Breeding

The second objective is developing improved red-fleshed apple lines.

Selections will focus on:

• Strong red foliage
• Red wood
• Red flesh
• Tree vigor
• Ornamental value
• Fruit quality

Because red-fleshed apples are already relatively uncommon, even successful ornamental selections have significant value while future generations continue improving fruit quality.

Current Updates 

The first phase of the Apple Rootstock Project began in December 2025 and continued through April 2026, with seeds being cold-stratified and subsequently grown indoors before being transitioned outdoors in early to mid-April. Later seeds were cold-stratified and moved directly into outdoor pots once their taproots emerged. The seedlings therefore experienced natural Pacific Northwest conditions relatively early in their development, including several periods at or below 32°F, with the lowest briefly approaching approximately 30°F. Some seedlings were lost during this period, likely as a result of cultivation errors involving nutrient availability, salt accumulation, and growing-medium conditions. Because of this, it is possible that some promising individuals were lost before they could be properly evaluated.

One of the more interesting observations has been the difference in growth patterns between individual seedlings. Cosmic Crisp seedlings in particular have displayed an unusual growth pattern, often producing relatively thin vertical growth before apparently slowing around 4–8 inches. Rather than continuing steadily upward, some seedlings appear to concentrate growth near the terminal region before producing a vigorous new flush from the tip. Whether this represents a genetic growth characteristic, environmental stress, root development, or a combination of factors remains unclear. A video documenting this behavior will be included below.

Individual seedlings have also demonstrated noticeably different growth habits. Some tend to produce more vigorous vertical shoots, while others develop shorter or more compact growth. Some of these characteristics could eventually prove useful when evaluating potential dwarfing or growth-habit traits, although environmental effects must be ruled out before assigning a genetic basis.

Top 9 Vigorous Seedlings

Notes. 

Red Foliage Observations

Red and bronze pigmentation has appeared on the stems and foliage of several seedlings. However, the coloration frequently becomes less pronounced as the seedlings mature. Red pigmentation also appears more frequently under stressful or non-optimal growing conditions.

For this reason, it is currently too early to determine whether the observed red coloration represents a stable genetic characteristic or simply a stress response. Future observations will focus on whether pigmentation persists under healthy, vigorous growth.

Current Seedling Selection

Approximately 8 Honeycrisp and Cosmic Crisp seedlings are currently being maintained in five-gallon containers to provide greater space for root development and continued vegetative growth.

The current selection strategy has also changed. Rather than retaining a large number of seedlings indefinitely, the strongest individuals will eventually be allowed to develop as full trees while the remaining suitable seedlings will be used for experimental grafting and rootstock trials.

Spring 2027 Grafting Candidates

At present, one of the leading seedlings has surpassed the previously strongest individual in overall vigor. Its continued growth will be monitored before making a permanent selection.

For now, the primary focus is observation and evaluation rather than grafting. Grafting trials will begin next spring as the established cultivated apple trees produce new growth suitable for scion material. Excess seedlings and grafting material may also eventually be made available.

Red-Fleshed Apple

The red-fleshed apple portion of the project is currently on hold because I’m deliberately giving my trees more time to develop and mature before I start sourcing fruit from them.

I actually had the option to let one apple develop on my red-fleshed tree this year, but I decided to remove it instead. I’d rather give the tree another season to focus on building a stronger root system and a more extensive canopy. That should put it in a better position to produce meaningful fruit next year.

Once the trees are mature enough to produce fruit reliably, I can start collecting seeds from them and gradually expand the red-fleshed portion of the project.

Notable Observations

Looking Forward

Store-bought seed provided an excellent starting point while establishing this project.

As my own orchard matures, nearly all future breeding work will come directly from my own trees, allowing greater control over parent selection and long-term breeding goals.