A future Martian colony will need to support itself by growing crops. Previous studies have shown that Martian regolith (Martian soil) is poor for growing crops. Although additions of organic soil boost crop growth, large shipments of soil to Mars are impractical. An easier resource to transport, mycorrhizal fungi are proven to significantly help the growth of romaine lettuce (Lactuca sativa). The research goal is to prove mycorrhizae can significantly improve lettuce growth in regolith compared to compost or organic soil. 6 groups of 4 pots with 8 seeds each grew for 32 days before harvest. Group 1 was pot soil. Group 2 was 75% pot soil 25% regolith. Group 3 was 25% pot soil 75% regolith. Group 4 was 100% regolith. Group 5 was regolith with 10ml mycorrhizae. Group 6 was pot soil with 10ml mycorrhizae. Measurements included lettuce height, leaf count, biomass, germination, and root length. The plants grew for 32 days. With mycorrhizae, Lactuca sativa had 118% more biomass and grew 63.3% taller in regolith than without mycorrhizae. Lactuca sativa with mycorrhizae in regolith had statistically insignificant growth compared to 25% pot soil. However, mycorrhizae-regolith had 48.7% less biomass than the control: potting soil. If compost cannot be transported to Mars, mycorrhizae could significantly improve the growth of crops. Future studies should focus on growing the Lactuca sativa until it is fully matured and confirm mycorrhizal association with plant roots.