Protea lacticolor is easily propagated and responds best when propagated by seed. Sow the seed in autumn (March to May) in a well-drained sowing medium, such as a mixture of coarse sand and finely milled pine bark. It is important to select the fertile seed before sowing. The fertile seeds are plump, whereas infertile ones are not. Protea seeds are very sensitive to waterlogging and humidity. Place them on a well-aerated sowing bench and use a free-draining container. Treating the seeds with smoke will improve germination. Place the seed trays in an airtight plastic tent and pipe in smoke from burning fynbos for 30 minutes. Allow the air to clear and then water the seed trays. Smoke extract can also be used. The seeds are soaked in the smoke extract for 24 hours and sown. Packets of the Kirstenbosch Instant Smoke Seed Primer are available for sale from the Seedroom. Treat your seed with a dusting systemic fungicide containing the active ingredient metalaxyl to prevent the post emergence seedling infection. The optimum temperature for germination of the seed is 5–10ºC for night temperature and 15–200C for day temperature.

After sowing, cover the seed with a light layer of sand to cover any exposed seed. Keep the soil moist and apply a fungicide once a week. To prevent birds and rodents from eating the seeds, cover the benches or trays with a grid. Once the seed has germinated, they will produce the cotyledons, followed by true leaves. The seedlings are ready to be transplanted into small plastic bags or into compartmentalized trays when they have true leaves. Once potted up, place them under the shade net for hardening off, particularly in dry and hot conditions. Plants grown from seed can begin to flower in 3 years after been propagated.

Protea lacticolor grows on nutrient-poor soil, more specifically where phosphorus is scarce. They have sensitive proteoid roots that can extract minute amounts of minerals from the soil. High levels of phosphates in the soil can be toxic to proteas. Feed proteas with light applications of an organic fertilizer to encourage the sensitive proteoid roots. Avoid using artificial fertilizers containing phosphorus, as they can cause protea plants to collapse and eventually die. Phosphate toxicity of the tip of young growth induces scorching or necrosis and cause the leaves to yellow.

Keep the soil moist during the hot, dry season by mulching your bed with a layer of mulch about 5 mm thick. Ensure that the mulch is free of Armillaria root rot, as they will spread to the plants. The mulch will keep the roots cool, keep moisture in the soil and reduce the growth of weeds. Chipping mulch is highly recommended, as they break down very slow and also release small amount of nutrients to the plant. The use of compost should be taken into consideration as it may burn the proteoids roots or change the texture of the soil.

Protea lacticolor requires little pruning. Pinch the tips of young plant regularly to encourage branching.