This is the fourth and final post in the strawberry anatomy blog series. Root systems are complex, and they can quietly determine how well your crop performs. Understanding how they function can help you make better decisions about irrigation, fertility, fumigation, and runner management.

Strawberries have a shallow, fibrous root system. In sandy soils, roots can grow as deep as 24 inches.  In heavy clay soils, most roots stay in the top six inches. Roots emerge from the base of the crown where it contacts the soil. Once they extend 1-2 inches, they begin branching (if moisture is adequate), eventually forming a fibrous mass.

Why this matters:

• Most of your water and nutrients need to be available in the upper soil profile.
• Over-irrigation in clay soils can easily create saturated conditions.
• Frequent, well-managed irrigation is critical because roots don’t explore very deep.

Strawberry roots fall into four categories, each with its own attributes and functions (Table 1).

Table 1. Root types and their lifespan, main function and importance to yield

Key takeaway: Your finest roots and root hairs are doing most of the work when it comes to water and nutrient uptake, and they are short-lived and fragile.  Anything that damages fine roots (salinity, overwatering, soil compaction, pathogens, fertilizer burn) directly impacts uptake and yield potential.

Strawberry roots exude chemicals that are autotoxic (toxic to itself). Why would any plant do that? These exudates direct root growth around obstacles in the soil, preventing competition from other plant roots and also to control root spacing and branching (Falik et al. 2005).

Movement of water and nutrients through the plant

Roots absorb water and nutrients, which move upward through the xylem via the transpiration stream. When leaves lose water through stomata (see part 3 – leaves and stems), it pulls more water up from the roots. Sugars produced in the leaves move through the phloem to sinks like fruit, roots, crown and new leaves. Unlike xylem (mostly upward movement), phloem moves sugars wherever the plant needs them.

Practical implication: Anything that reduces transpiration (high humidity, low light, poor leaf health) can slow nutrient movement. Healthy foliage supports healthy root function and vice versa.

Strawberry roots naturally form associations with arbuscular mycorrhizal (AM) fungi. That’s a technical term for a soil fungus that colonizes roots and forms tiny arbuscules (tiny tree-shaped structures) inside the root. Unlike soilborne fungal pathogens, AM fungi form a symbiotic relationship with the plant, extending the effective root system and improving nutrient and water uptake. There are many commercial AM products on the market designed to facilitate this natural process. While strawberries naturally host these fungi, trials we’ve conducted with a few commercially formulated products have not shown an increase in yield, plant size or vigor. 

The crown: the command center

The crown sits between the roots and the above-ground plant parts, slightly above the soil line. It is the plant’s central control hub. At the tip of the crown lies the apical meristem (Figs. 1 and 3), responsible for producing new leaves and flowers. If you carefully peel back young leaves in the center of the plant, the tiny dome-shaped growing point underneath is the apical meristem. Axillary buds are found at the base of each leaf and can develop into branch crowns, stolons/runners and flower clusters. Each branch crown can produce its own flowers, directly influencing yield potential. You can find tiny versions of all these structures at the base of each leaf and researchers are looking into this as a way of forecasting yield 10-12 weeks into the future (Savini et al. 2005).

Unlike leaves and fruit, the crown is the perennial survival organ.  It serves to store energy accumulated during the growing season. This part of the crown’s function is important for multi-year production systems — rare in California but common in gardens and in nature.  The crown also mediates the plant’s reproductive switch between vegetative growth (leaf and runner production) and reproductive growth (flower initiation).

Runners: critical for the nursery and a nuisance for growers

Stolons or ‘runners’ are produced from the crown and extend outward to form two nodes: one dormant and the other producing a ‘daughter plant’. Stolons are a nuisance to growers who must remove them manually to prevent the plant’s resources from being diverted to propagation instead of fruit production.  However, without stolons, nurseries would not be able to produce the millions of daughter plants necessary for planting over 40,000 acres of strawberries in the state. Our automation team is working on an automated system for identifying and cutting runners using inexpensive laser technology.

What does this all mean for growers?

If we step back, here are the practical lessons:

1. Most roots are shallow → Manage irrigation carefully.
2. Fine roots drive yield → Protect them from stress.
3. Root health equals nutrient efficiency → Salinity and soil structure matter.
4. The crown determines yield potential → Early plant health sets the season.
5. Runner management protects fruit production.

That’s a wrap on the strawberry anatomy series. Understanding how the plant is built helps us make better decisions, communicate more effectively, and ultimately grow a better crop.

References:

Falik, O., Reides, P., Gersani, M. and Novoplansky, A. 2005. Root navigation by self inhibition. Plant, Cell and Environment 28:562-569. https://onlinelibrary.wiley.com/doi/10.1111/j.1365-3040.2005.01304.x

Savini, G., Neri, D., Mercadante, L., Molari, G., Magnani, D., and Capriolo, G. 2006. Meristem analysis on strawberry plants during propagation and production. Acta Hort. 708:237–240. https://doi.org/10.17660/ActaHortic.2006.708.38