Almond orchard with 'Penta' and 'Makako' trees blooming despite frost.

Late Bloomers: How New Almond Varieties Can Beat the Frost

Reese Marlowe in Science & Nature August 2025 • 4 min read.

"Discover how 'Penta' and 'Makako', two extra-late flowering almond cultivars, are revolutionizing almond cultivation in frost-prone regions, ensuring a sweeter harvest for growers."

For centuries, almond cultivation has been at the mercy of unpredictable spring frosts. A late cold snap during the flowering season can devastate entire crops, leaving farmers with significant losses. Traditional almond varieties, with their earlier bloom times, are particularly vulnerable. However, the game is changing thanks to innovative breeding programs focused on developing extra-late flowering cultivars.

The Centro de Edafología y Biología Aplicada del Segura-Consejo Superior de Investigaciones Científicas (CEBAS-CSIC) in Spain has been at the forefront of this effort. Since 1971, their almond breeding program has aimed to create self-compatible and late-flowering varieties. This research has led to the development of groundbreaking cultivars like 'Penta' and 'Makako,' which are transforming almond cultivation in colder regions.

These new cultivars not only offer protection against frost damage but also provide numerous other benefits for growers, including simplified orchard management and increased yields. As climate patterns become more erratic, the importance of these frost-resistant varieties will only continue to grow.

The Science Behind Late Bloomers

Almond orchard with 'Penta' and 'Makako' trees blooming despite frost.

The key to 'Penta' and 'Makako' lies in their significantly delayed flowering times. 'Penta' blooms approximately 15 days later than the standard 'Ferragnès' variety (and a full 23 days later than 'Nonpareil'), while 'Makako' flowers about two days before 'Penta'. This delay, though seemingly small, makes a huge difference in avoiding frost damage. This is achieved through careful cross-breeding, leveraging genetic traits that control flowering time and self-compatibility.

Self-compatibility is another crucial characteristic of these cultivars. Unlike traditional almond varieties that require cross-pollination with different trees, 'Penta' and 'Makako' can be pollinated by their own pollen. This offers several advantages:

Simplified Orchard Management: Growers can cultivate entire orchards with a single cultivar, eliminating the need for pollinizer trees.
Efficient Pollination: Every tree contributes to the yield, maximizing production.
Reduced Dependence on Bees: While beehives are still recommended to boost production, the self-compatibility of these varieties reduces reliance on external pollinators, which can be affected by weather and other environmental factors.
Streamlined Harvesting: Harvesting can be completed in one go, reducing labor costs and simplifying storage.

The origins of 'Penta' and 'Makako' are equally interesting. 'Penta' is derived from a cross between 'S5133' and 'Lauranne,' while 'Makako' is the result of a reciprocal cross between the same two parents. This means that although they share the same genetic lineage, the order in which the parents were crossed resulted in distinct characteristics. 'S5133' is a late-blooming selection from CEBAS-CSIC, while 'Lauranne' is a self-compatible and late-flowering cultivar from France.

A Sweet Future for Almond Growers

With almond prices on the rise and cultivation expanding into regions prone to frost, cultivars like 'Penta' and 'Makako' offer a promising solution for growers. These extra-late flowering, self-compatible varieties not only minimize the risk of crop loss but also simplify orchard management and potentially increase yields. Whether you're a large-scale producer or a small family farm, these innovative cultivars are paving the way for a more secure and sustainable future for almond cultivation. For growers looking to diversify their crops, 'Makako' is an excellent complement to 'Penta', staggering the harvest and mitigating risk.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.21273/hortsci13310-18, Alternate LINK

Title: Penta And Makako: Two Extra-Late Flowering Self-Compatible Almond Cultivars From Cebas-Csic

Subject: Horticulture

Journal: HortScience

Publisher: American Society for Horticultural Science

Authors: Federico Dicenta, Teresa Cremades, Pedro José Martínez-García, Pedro Martínez-Gómez, Encarnación Ortega, Manuel Rubio, Raquel Sánchez-Pérez, Jesús López-Alcolea, José Egea

Published: 2018-11-01

Everything You Need To Know

What are the key characteristics of the 'Penta' and 'Makako' almond varieties, and how do they differ from traditional almonds?

The 'Penta' and 'Makako' almond varieties are extra-late flowering cultivars developed by CEBAS-CSIC in Spain. 'Penta' blooms approximately 15 days later than 'Ferragnès' and 23 days later than 'Nonpareil', while 'Makako' flowers about two days before 'Penta'. This delayed flowering helps them avoid frost damage, which is especially beneficial in regions with unpredictable spring weather. They are also self-compatible, meaning they don't require cross-pollination.

What does self-compatibility mean for almond cultivation, specifically in the context of cultivars like 'Penta' and 'Makako'?

Self-compatibility in almond cultivars like 'Penta' and 'Makako' means that the trees can be pollinated by their own pollen, eliminating the need for separate pollinizer trees. This simplifies orchard management, ensures every tree contributes to the yield, reduces dependence on external pollinators like bees (though beehives are still recommended to boost production), and streamlines harvesting. Traditional almond varieties require cross-pollination, making self-compatibility a significant advantage.

Can you explain the genetic origins of the 'Penta' and 'Makako' almond cultivars?

'Penta' is derived from a cross between 'S5133' and 'Lauranne,' while 'Makako' comes from a reciprocal cross between the same parents. 'S5133' is a late-blooming selection from CEBAS-CSIC, and 'Lauranne' is a self-compatible, late-flowering cultivar from France. The reciprocal cross means that even though they share genetic lineage, the order in which the parent plants were crossed resulted in distinct characteristics for each cultivar.

How do 'Penta' and 'Makako' contribute to more sustainable almond farming practices?

Growing 'Penta' and 'Makako' can lead to more sustainable almond farming because of their frost resistance and self-compatibility. Frost resistance minimizes crop loss due to late cold snaps, ensuring more consistent yields. Self-compatibility reduces the need for pollinizers and lowers the dependence on bee populations. These factors contribute to more reliable harvests and potentially reduce the environmental impact associated with managing traditional almond orchards. Diversifying with both 'Makako' and 'Penta' also allows for staggered harvesting which decreases risk.

What is the history and focus of the CEBAS-CSIC almond breeding program that led to the creation of 'Penta' and 'Makako'?

CEBAS-CSIC's almond breeding program has been working since 1971 to develop self-compatible and late-flowering almond varieties. Their breeding program focuses on cross-breeding, leveraging genetic traits that control flowering time and self-compatibility. The development of 'Penta' and 'Makako' represents a major advancement in this field, offering growers a solution to the challenges posed by climate change and frost-prone environments, while also simplifying orchard management.