Environmental processes to recover degraded areas, as well as the conservation of Brazilian forests and biomes, have intensified interest in the propagation of native species, triggering an increase in demand for the production of seeds and seedlings. Among the plants with a high potential for reforestation is the ipê, of all colors, a species suitable for reforestation, urban afforestation, landscaping, or domestic planting. This study aimed to evaluate the morphological characteristics of ipê-roxo as a function of doses of hydro-absorbent polymer in the open field. The experiment was carried out in 14 L pots in the area of the UNINTA University Center, in the municipality of Tianguá, on the Ibiapaba plateau, in a randomized block design, testing three doses of hydro-absorbent polymer (0.0, 3.0, and 6.0 g kg-1) applied in the hole before transplanting the ipê-roxo seedlings, with five replications. The plant's morphological characteristics were assessed, such as number of leaves, plant height, and stem diameter. The data was subjected to the normality test and Tukey's test at a 5% significance level. It was found that there were no significant results about the treatments used in the experiment; the different doses of hydro-absorbent polymer did not influence any of the variables analyzed, as shown in the analysis of variance, at 30, 60, and 90 DAT. We conclude that the null hypothesis is accepted, there is no difference between the treatments and the control, indicating that polymer doses of up to 6.0 g kg-1 do not influence the morphological aspect of ipê-roxo up to 90 days.